Run GCP Integration tests for catalog

[rambleraptor]

Feature Request / Improvement

We need to run the integration tests for the Metastore Catalog on PRs:

• Get GCP project credentials setup on GitHub
• Include them on GitHub Action
• General test cleanup
• Add integration tests for Google AuthManager

[jayceslesar]

Do you think its possible to set up this in a way where we can plug them into this https://github.com/apache/iceberg-python/blob/main/tests/integration/test_catalog.py ?

Would be epic to get all catalogs testing under a common suite

[Fokko]

@rambleraptor Could you raise this on the dev-list? If we have agreement here (I'm all in), then we can link that thread in a ASF Infra issue