As seen in https://gitlab.com/gitlab-org/gitlab/-/issues/327416,
previously Rack Attack throttled
`/api/v4/container_registry_event/events`, which then caused Rack Attack
to rate limit on other unauthenticated requests, such as fetches to
remote CI YAML files.

Since this is a trusted request from the Docker API, we can exempt this
from our rate limiting. We now skip the request if the path starts with
`/api/v4/container_registry_event/`.  We now skip the request if the
path starts with `/api/v4/container_registry_event/`.

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/327416