Ignore terraform GCS source

[nguymin4]

What are you trying to accomplish?

Related to #5603

Terraform supports GCS bucket as module source https://developer.hashicorp.com/terraform/language/modules/sources#gcs-bucket

But currently dependabot fails with error

Unknown src: gcs::https://www.googleapis.com/storage/v1/modules/foomodule.zip

This PR fixes the Unknown src error but also ignore GCS source as it usually requires authentication and can be somewhat complex. Based on #5603 S3 doesn't seems to work currently either.

Anything you want to highlight for special attention from reviewers?

I had a test for #source_type. However I couldn't find any tests for #source_from

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.