Remove unnecessary require_relative calls from service classes

Rails by default use autoload for all dirs from app folder.
require_relative not needed. See ActiveSupport::Dependencies.autoload_paths

app/services/after_branch_delete_service.rb

-require_relative 'base_service'
-
 ##
 # Branch can be deleted either by DeleteBranchService
 # or by GitPushService.

app/services/create_branch_service.rb

-require_relative 'base_service'
-
 class CreateBranchService < BaseService
   def execute(branch_name, ref, source_project: @project)
     valid_branch = Gitlab::GitRefValidator.validate(branch_name)

app/services/create_deployment_service.rb

-require_relative 'base_service'
-
 class CreateDeploymentService < BaseService
   def execute(deployable = nil)
     return unless executable?

app/services/create_release_service.rb

-require_relative 'base_service'
-
 class CreateReleaseService < BaseService
   def execute(tag_name, release_description)
     repository = project.repository

app/services/create_tag_service.rb

-require_relative 'base_service'
-
 class CreateTagService < BaseService
   def execute(tag_name, target, message, release_description = nil)
     valid_tag = Gitlab::GitRefValidator.validate(tag_name)

app/services/delete_branch_service.rb

-require_relative 'base_service'
-
 class DeleteBranchService < BaseService
   def execute(branch_name)
     repository = project.repository

app/services/delete_merged_branches_service.rb

-require_relative 'base_service'
-
 class DeleteMergedBranchesService < BaseService
   def async_execute
     DeleteMergedBranchesWorker.perform_async(project.id, current_user.id)

app/services/delete_tag_service.rb

-require_relative 'base_service'
-
 class DeleteTagService < BaseService
   def execute(tag_name)
     repository = project.repository

app/services/files/create_dir_service.rb

-require_relative "base_service"
-
 module Files
   class CreateDirService < Files::BaseService
     def commit

app/services/files/create_service.rb

-require_relative "base_service"
-
 module Files
   class CreateService < Files::BaseService
     def commit

app/services/files/delete_service.rb

-require_relative "base_service"
-
 module Files
   class DeleteService < Files::BaseService
     def commit

app/services/files/multi_service.rb

-require_relative "base_service"
-
 module Files
   class MultiService < Files::BaseService
     class FileChangedError < StandardError; end

app/services/files/update_service.rb

-require_relative "base_service"
-
 module Files
   class UpdateService < Files::BaseService
     class FileChangedError < StandardError; end

app/services/merge_requests/update_service.rb

-require_relative 'base_service'
-require_relative 'reopen_service'
-require_relative 'close_service'
-
 module MergeRequests
   class UpdateService < MergeRequests::BaseService
     def execute(merge_request)

app/services/update_release_service.rb

-require_relative 'base_service'
-
 class UpdateReleaseService < BaseService
   def execute(tag_name, release_description)
     repository = project.repository

changelogs/unreleased/remove-require-from-services.yml

+---
+title: 'Remove unnecessary require_relative calls from service classes'
+merge_request: '7601'
+author: Semyon Pupkov