Draft: Cloud Connector: log JWKS changes

This reflects a change back that we recently made to the AI gateway and that will log any changes to the JSON Web Key Set after performing OIDC key discovery.

See also:

• https://gitlab.com/gitlab-org/modelops/applied-ml/code-suggestions/ai-assist/-/issues/640
• gitlab-org/modelops/applied-ml/code-suggestions/ai-assist!1436 (merged) for the original change.