Enable frozen string in app/graphql + app/finders

Partially addresses #47424.

app/finders/access_requests_finder.rb

+# frozen_string_literal: true
+
 class AccessRequestsFinder
   attr_accessor :source

app/finders/admin/projects_finder.rb

+# frozen_string_literal: true
+
 class Admin::ProjectsFinder
   attr_reader :params, :current_user

app/finders/branches_finder.rb

+# frozen_string_literal: true
+
 class BranchesFinder
   def initialize(repository, params = {})
     @repository = repository

app/finders/clusters_finder.rb

+# frozen_string_literal: true
+
 class ClustersFinder
   def initialize(project, user, scope)
     @project = project

app/finders/concerns/created_at_filter.rb

+# frozen_string_literal: true
+
 module CreatedAtFilter
   def by_created_at(items)
     items = items.created_before(params[:created_before]) if params[:created_before].present?

app/finders/concerns/custom_attributes_filter.rb

+# frozen_string_literal: true
+
 module CustomAttributesFilter
   def by_custom_attributes(items)
     return items unless params[:custom_attributes].is_a?(Hash)

app/finders/concerns/finder_methods.rb

+# frozen_string_literal: true
+
 module FinderMethods
   def find_by!(*args)
     raise_not_found_unless_authorized execute.find_by!(*args)

app/finders/concerns/finder_with_cross_project_access.rb

+# frozen_string_literal: true
+
 # Module to prepend into finders to specify wether or not the finder requires
 # cross project access
 #

app/finders/contributed_projects_finder.rb

+# frozen_string_literal: true
+
 class ContributedProjectsFinder < UnionFinder
   def initialize(user)
     @user = user

app/finders/environments_finder.rb

+# frozen_string_literal: true
+
 class EnvironmentsFinder
   attr_reader :project, :current_user, :params

app/finders/events_finder.rb

+# frozen_string_literal: true
+
 class EventsFinder
   prepend FinderMethods
   prepend FinderWithCrossProjectAccess

app/finders/fork_projects_finder.rb

+# frozen_string_literal: true
+
 class ForkProjectsFinder < ProjectsFinder
   def initialize(project, params: {}, current_user: nil)
     project_ids = project.forks.includes(:creator).select(:id)

app/finders/group_descendants_finder.rb

+# frozen_string_literal: true
+
 # GroupDescendantsFinder
 #
 # Used to find and filter all subgroups and projects of a passed parent group

app/finders/group_finder.rb

+# frozen_string_literal: true
+
 class GroupFinder
   include Gitlab::Allowable

app/finders/group_members_finder.rb

+# frozen_string_literal: true
+
 class GroupMembersFinder
   def initialize(group)
     @group = group

app/finders/group_projects_finder.rb

+# frozen_string_literal: true
+
 # GroupProjectsFinder
 #
 # Used to filter Projects  by set of params

app/finders/groups_finder.rb

+# frozen_string_literal: true
+
 # GroupsFinder
 #
 # Used to filter Groups by a set of params

app/finders/issuable_finder.rb

+# frozen_string_literal: true
+
 # IssuableFinder
 #
 # Used to filter Issues and MergeRequests collections by set of params

app/finders/issues_finder.rb

+# frozen_string_literal: true
+
 # Finders::Issues class
 #
 # Used to filter Issues collections by set of params

app/finders/joined_groups_finder.rb

+# frozen_string_literal: true
+
 class JoinedGroupsFinder < UnionFinder
   def initialize(user)
     @user = user