Remove unused web_ide_default feature flag

This flag has been introduced over a year ago in
https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/25171
and hasn't been turned on since. This cleanup removes it in favour
of testing different button highlighting.

app/helpers/blob_helper.rb

@@ -52,13 +52,12 @@ module BlobHelper
     edit_button_tag(blob,
                     common_classes,
                     _('Edit'),
-                    Feature.enabled?(:web_ide_default) ? ide_edit_path(project, ref, path) : edit_blob_path(project, ref, path, options),
+                    edit_blob_path(project, ref, path, options),
                     project,
                     ref)
   end
 
   def ide_edit_button(project = @project, ref = @ref, path = @path, blob:)
-    return if Feature.enabled?(:web_ide_default)
     return unless blob
 
     edit_button_tag(blob,

app/serializers/diff_file_base_entity.rb

@@ -26,14 +26,10 @@ class DiffFileBaseEntity < Grape::Entity
 
     target_project, target_branch = edit_project_branch_options(merge_request)
 
-    if Feature.enabled?(:web_ide_default)
-      ide_edit_path(target_project, target_branch, diff_file.new_path)
-    else
     options = merge_request.persisted? && merge_request.source_branch_exists? && !merge_request.merged? ? { from_merge_request_iid: merge_request.iid } : {}
 
     project_edit_blob_path(target_project, tree_join(target_branch, diff_file.new_path), options)
   end
-  end
 
   expose :old_path_html do |diff_file|
     old_path, _ = mark_inline_diffs(diff_file.old_path, diff_file.new_path)

spec/features/merge_request/maintainer_edits_fork_spec.rb

@@ -20,7 +20,7 @@ RSpec.describe 'a maintainer edits files on a source-branch of an MR from a fork
   end
 
   before do
-    stub_feature_flags(web_ide_default: false, single_mr_diff_view: false)
+    stub_feature_flags(single_mr_diff_view: false)
 
     target_project.add_maintainer(user)
     sign_in(user)

spec/features/projects/blobs/edit_spec.rb

@@ -11,10 +11,6 @@ RSpec.describe 'Editing file blob', :js do
   let(:file_path) { project.repository.ls_files(project.repository.root_ref)[1] }
   let(:readme_file_path) { 'README.md' }
 
-  before do
-    stub_feature_flags(web_ide_default: false)
-  end
-
   context 'as a developer' do
     let(:user) { create(:user) }
     let(:role) { :developer }

spec/features/projects/files/user_creates_files_spec.rb

@@ -14,8 +14,6 @@ RSpec.describe 'Projects > Files > User creates files', :js do
   let(:user) { create(:user) }
 
   before do
-    stub_feature_flags(web_ide_default: false)
-
     project.add_maintainer(user)
     sign_in(user)
   end

spec/features/projects/files/user_edits_files_spec.rb

@@ -11,8 +11,6 @@ RSpec.describe 'Projects > Files > User edits files', :js do
   let(:user) { create(:user) }
 
   before do
-    stub_feature_flags(web_ide_default: false)
-
     sign_in(user)
   end
 

spec/helpers/blob_helper_spec.rb

@@ -53,20 +53,12 @@ RSpec.describe BlobHelper do
     end
 
     it 'returns a link with the proper route' do
-      stub_feature_flags(web_ide_default: false)
       link = helper.edit_blob_button(project, 'master', 'README.md')
 
       expect(Capybara.string(link).find_link('Edit')[:href]).to eq("/#{project.full_path}/-/edit/master/README.md")
     end
 
-    it 'returns a link with a Web IDE route' do
-      link = helper.edit_blob_button(project, 'master', 'README.md')
-
-      expect(Capybara.string(link).find_link('Edit')[:href]).to eq("/-/ide/project/#{project.full_path}/edit/master/-/README.md")
-    end
-
     it 'returns a link with the passed link_opts on the expected route' do
-      stub_feature_flags(web_ide_default: false)
       link = helper.edit_blob_button(project, 'master', 'README.md', link_opts: { mr_id: 10 })
 
       expect(Capybara.string(link).find_link('Edit')[:href]).to eq("/#{project.full_path}/-/edit/master/README.md?mr_id=10")

spec/serializers/diff_file_base_entity_spec.rb

@@ -40,10 +40,6 @@ RSpec.describe DiffFileBaseEntity do
     let(:options) { { request: EntityRequest.new(current_user: create(:user)), merge_request: merge_request } }
     let(:params) { {} }
 
-    before do
-      stub_feature_flags(web_ide_default: false)
-    end
-
     shared_examples 'a diff file edit path to the source branch' do
       it do
         expect(entity[:edit_path]).to eq(Gitlab::Routing.url_helpers.project_edit_blob_path(project, File.join(merge_request.source_branch, diff_file.new_path), params))