Release the merge request diff replication

- Add changelog releasing the merge request diff replication
- Updated documentation about replicated types
- Default geo_merge_request_diff_replication to true

Relates to https://gitlab.com/gitlab-org/gitlab/issues/247100

doc/api/graphql/reference/gitlab_schema.graphql

@@ -7224,8 +7224,7 @@ type GeoNode {
   internalUrl: String
 
   """
-  Find merge request diff registries on this Geo node. Available only when
-  feature flag `geo_merge_request_diff_replication` is enabled
+  Find merge request diff registries on this Geo node
   """
   mergeRequestDiffRegistries(
     """

doc/api/graphql/reference/gitlab_schema.json

@@ -19906,7 +19906,7 @@
             },
             {
               "name": "mergeRequestDiffRegistries",
-              "description": "Find merge request diff registries on this Geo node. Available only when feature flag `geo_merge_request_diff_replication` is enabled",
+              "description": "Find merge request diff registries on this Geo node",
               "args": [
                 {
                   "name": "ids",

ee/app/graphql/types/geo/geo_node_type.rb

@@ -25,8 +25,7 @@ module Types
       field :merge_request_diff_registries, ::Types::Geo::MergeRequestDiffRegistryType.connection_type,
             null: true,
             resolver: ::Resolvers::Geo::MergeRequestDiffRegistriesResolver,
-            description: 'Find merge request diff registries on this Geo node',
-            feature_flag: :geo_merge_request_diff_replication
+            description: 'Find merge request diff registries on this Geo node'
       field :package_file_registries, ::Types::Geo::PackageFileRegistryType.connection_type,
             null: true,
             resolver: ::Resolvers::Geo::PackageFileRegistriesResolver,

ee/app/replicators/geo/merge_request_diff_replicator.rb

@@ -8,10 +8,6 @@ module Geo
       ::MergeRequestDiff
     end
 
-    def self.replication_enabled_by_default?
-      false
-    end
-
     def self.primary_total_count
       model.has_external_diffs.count
     end

ee/changelogs/unreleased/247100-remove_feature_flag_for_merge_request_diffs.yml

+---
+title: Enable geo replication for merge request diffs
+merge_request: 45224
+author:
+type: added

ee/config/feature_flags/development/geo_merge_request_diff_replication.yml

@@ -4,4 +4,4 @@ introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/34248
 rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/247100
 group: group::geo
 type: development
-default_enabled: false
\ No newline at end of file
+default_enabled: true

ee/spec/workers/geo/secondary/registry_consistency_worker_spec.rb

@@ -111,23 +111,6 @@ RSpec.describe Geo::Secondary::RegistryConsistencyWorker, :geo do
       expect(Geo::UploadRegistry.where(file_id: upload.id).count).to eq(1)
     end
 
-    context 'when geo_merge_request_diff_replication is disabled' do
-      before do
-        stub_feature_flags(geo_merge_request_diff_replication: false)
-      end
-
-      it 'returns false' do
-        expect(subject.perform).to be_falsey
-      end
-
-      it 'does not execute RegistryConsistencyService for merge request diffs' do
-        allow(Geo::RegistryConsistencyService).to receive(:new).and_call_original
-        expect(Geo::RegistryConsistencyService).not_to receive(:new).with(Geo::MergeRequestDiffRegistry, batch_size: batch_size)
-
-        subject.perform
-      end
-    end
-
     context 'when the current Geo node is disabled or primary' do
       before do
         stub_primary_node