Enable frozen string for GitHub import specs

Partially addresses:

https://gitlab.com/gitlab-org/gitlab/issues/27703

spec/lib/gitlab/github_import/bulk_importing_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::BulkImporting do

spec/lib/gitlab/github_import/caching_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Caching, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/client_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Client do

spec/lib/gitlab/github_import/importer/diff_note_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::DiffNoteImporter do

spec/lib/gitlab/github_import/importer/diff_notes_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::DiffNotesImporter do

spec/lib/gitlab/github_import/importer/issue_and_label_links_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::IssueAndLabelLinksImporter do

spec/lib/gitlab/github_import/importer/issue_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::IssueImporter, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/importer/issues_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::IssuesImporter do

spec/lib/gitlab/github_import/importer/label_links_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::LabelLinksImporter do

spec/lib/gitlab/github_import/importer/labels_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::LabelsImporter, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/importer/lfs_object_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::LfsObjectImporter do

spec/lib/gitlab/github_import/importer/lfs_objects_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::LfsObjectsImporter do

spec/lib/gitlab/github_import/importer/milestones_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::MilestonesImporter, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/importer/note_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::NoteImporter do

spec/lib/gitlab/github_import/importer/notes_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::NotesImporter do

spec/lib/gitlab/github_import/importer/pull_request_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::PullRequestImporter, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/importer/pull_requests_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::PullRequestsImporter do

spec/lib/gitlab/github_import/importer/releases_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::ReleasesImporter do

spec/lib/gitlab/github_import/importer/repository_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Importer::RepositoryImporter do

spec/lib/gitlab/github_import/issuable_finder_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::IssuableFinder, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/label_finder_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::LabelFinder, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/markdown_text_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::MarkdownText do

spec/lib/gitlab/github_import/milestone_finder_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::MilestoneFinder, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/page_counter_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::PageCounter, :clean_gitlab_redis_cache do

spec/lib/gitlab/github_import/parallel_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::ParallelImporter do

spec/lib/gitlab/github_import/parallel_scheduling_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::ParallelScheduling do

spec/lib/gitlab/github_import/representation/diff_note_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Representation::DiffNote do

spec/lib/gitlab/github_import/representation/expose_attribute_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Representation::ExposeAttribute do

spec/lib/gitlab/github_import/representation/issue_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Representation::Issue do

spec/lib/gitlab/github_import/representation/note_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Representation::Note do

spec/lib/gitlab/github_import/representation/pull_request_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Representation::PullRequest do

spec/lib/gitlab/github_import/representation/to_hash_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Representation::ToHash do

spec/lib/gitlab/github_import/representation/user_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Representation::User do

spec/lib/gitlab/github_import/representation_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::Representation do

spec/lib/gitlab/github_import/sequential_importer_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::SequentialImporter do

spec/lib/gitlab/github_import/user_finder_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::GithubImport::UserFinder, :clean_gitlab_redis_cache do