Update feature category from pods to cell

app/workers/all_queues.yml

...database/ci_namespace_mirrors_consistency_check_worker.rb

...s/database/ci_project_mirrors_consistency_check_worker.rb

app/workers/loose_foreign_keys/cleanup_worker.rb

app/workers/namespaces/process_sync_events_worker.rb

app/workers/projects/process_sync_events_worker.rb

config/feature_categories.yml

db/docs/ci_namespace_mirrors.yml

db/docs/ci_project_mirrors.yml

db/docs/loose_foreign_keys_deleted_records.yml

db/docs/namespaces_sync_events.yml

db/docs/projects_sync_events.yml

spec/initializers/check_forced_decomposition_spec.rb

spec/initializers/load_balancing_spec.rb

spec/lib/gitlab/database/consistency_checker_spec.rb

spec/lib/gitlab/database/load_balancing_spec.rb

spec/lib/gitlab/database/lock_writes_manager_spec.rb

...migration_helpers/automatic_lock_writes_on_tables_spec.rb

...database/migration_helpers/restrict_gitlab_schema_spec.rb

...uery_analyzers/gitlab_schemas_validate_connection_spec.rb