fix(gcp): use InitializationError instead of panic in gcs-bucket and cloud-function

[Amit2465]

Description

Fixes the client initialization error handling in gcs-bucket and cloud-function resources. Both were using panic() when the GCP client failed to initialize, which would crash the process if the API is disabled. Updated to set r.InitializationError and return instead.

TODOs

• Run the relevant tests successfully, including pre-commit checks.
• Include release notes. If this PR is backward incompatible, include a migration guide.

Release Notes (draft)

Updated gcs-bucket and cloud-function to gracefully handle client initialization failures instead of panicking.

[Amit2465]

Hey @james00012, looks like #1062 handles this at the adapter level by adding a recover() in GcpResourceAdapter.Init(), which is a cleaner approach than fixing each resource individually. Closing this PR since it's covered there.