This is a small change to move AfterCommitQueue.inside_transaction?
to Gitlab::Database.inside_transaction? Since this change is required
by different changes which may not arrive in sequence, it's easier
to extract this change out on it's own.

Enables frozen for the following:

* lib/*.rb
* lib/banzai/**/*.rb
* lib/bitbucket/**/*.rb
* lib/constraints/**/*.rb
* lib/container_registry/**/*.rb
* lib/declarative_policy/**/*.rb

Partially addresses #47424.