Merge branch 'mk-fix-schema-dump-of-untracked-files-for-uploads' into 'master'

Ignore temporary table in schema

Closes #40976

See merge request gitlab-org/gitlab-ce!15866

changelogs/unreleased/mk-fix-schema-dump-of-untracked-files-for-uploads.yml

+---
+title: Fix error during schema dump.
+merge_request: 15866
+author:
+type: fixed

config/initializers/active_record_schema_ignore_tables.rb

+# Ignore table used temporarily in background migration
+ActiveRecord::SchemaDumper.ignore_tables = ["untracked_files_for_uploads"]