Remove branch_push_merge_commit_analyze flag

This has been stable

app/services/merge_requests/refresh_service.rb

@@ -85,18 +85,13 @@ module MergeRequests
 
       return if merge_requests.empty?
 
-      commit_analyze_enabled = Feature.enabled?(:branch_push_merge_commit_analyze, @project, default_enabled: true)
-      if commit_analyze_enabled
       analyzer = Gitlab::BranchPushMergeCommitAnalyzer.new(
         @commits.reverse,
         relevant_commit_ids: merge_requests.map(&:diff_head_sha)
       )
-      end
 
       merge_requests.each do |merge_request|
-        if commit_analyze_enabled
         merge_request.merge_commit_sha = analyzer.get_merge_commit(merge_request.diff_head_sha)
-        end
 
         MergeRequests::PostMergeService
           .new(merge_request.target_project, @current_user)

config/feature_flags/development/branch_push_merge_commit_analyze.yml

----
-name: branch_push_merge_commit_analyze
-introduced_by_url: 
-rollout_issue_url: 
-group: 
-type: development
-default_enabled: true

spec/services/merge_requests/refresh_service_spec.rb

@@ -796,10 +796,6 @@ RSpec.describe MergeRequests::RefreshService do
     subject { service.execute(oldrev, newrev, 'refs/heads/merge-commit-analyze-before') }
 
     context 'feature enabled' do
-      before do
-        stub_feature_flags(branch_push_merge_commit_analyze: true)
-      end
-
       it "updates merge requests' merge_commits" do
         expect(Gitlab::BranchPushMergeCommitAnalyzer).to receive(:new).and_wrap_original do |original_method, commits|
           expect(commits.map(&:id)).to eq(%w{646ece5cfed840eca0a4feb21bcd6a81bb19bda3 29284d9bcc350bcae005872d0be6edd016e2efb5 5f82584f0a907f3b30cfce5bb8df371454a90051 8a994512e8c8f0dfcf22bb16df6e876be7a61036 689600b91aabec706e657e38ea706ece1ee8268f db46a1c5a5e474aa169b6cdb7a522d891bc4c5f9})
@@ -816,24 +812,6 @@ RSpec.describe MergeRequests::RefreshService do
         expect(merge_request_side_branch.merge_commit.id).to eq('29284d9bcc350bcae005872d0be6edd016e2efb5')
       end
     end
-
-    context 'when feature is disabled' do
-      before do
-        stub_feature_flags(branch_push_merge_commit_analyze: false)
-      end
-
-      it "does not trigger analysis" do
-        expect(Gitlab::BranchPushMergeCommitAnalyzer).not_to receive(:new)
-
-        subject
-
-        merge_request.reload
-        merge_request_side_branch.reload
-
-        expect(merge_request.merge_commit).to eq(nil)
-        expect(merge_request_side_branch.merge_commit).to eq(nil)
-      end
-    end
   end
 
   describe '#abort_ff_merge_requests_with_when_pipeline_succeeds' do