Rename foreign key constraint

See
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/65201#note_673679338

db/post_migrate/20210907211557_finalize_ci_builds_bigint_conversion.rb

@@ -69,7 +69,7 @@ class FinalizeCiBuildsBigintConversion < Gitlab::Database::Migration[1.0]
     [:ci_build_trace_chunks, :build_id, :cascade, 'fk_rails_'],
     [:ci_build_trace_metadata, :build_id, :cascade, 'fk_rails_'],
     [:ci_builds_runner_session, :build_id, :cascade, 'fk_rails_'],
-    [:ci_builds_metadata, :build_id, :cascade, 'fk_rails_'],
+    [:ci_builds_metadata, :build_id, :cascade, 'fk_'],
     [:ci_job_artifacts, :job_id, :cascade, 'fk_rails_'],
     [:ci_job_variables, :job_id, :cascade, 'fk_rails_'],
     [:ci_pending_builds, :build_id, :cascade, 'fk_rails_'],