Update Pipeline to Pull Image from GCR, update Github Actions

[hunterpack]

What problem does your feature solve?

Our current pipeline only pushes Docker images to Docker Hub. This creates a dependency on a third-party registry, leading to potential rate limits and slower pull times in GCP environments. Our composer needs to access it with credentials.

What would you like to see?

We need to update our GitHub Actions CI/CD pipeline to support the following:

1. Dual-Push Mechanism: For all built images, the pipeline must push to both the existing Docker Hub and the new GCR location in our shared registry.
2. Production Image Replication: All production-tagged images (e.g., from main or release branches) must also be replicated and pushed to the GCR instance within each target Google Cloud Project (hubble, test-hubble, etc.).
3. GCR Authentication: Update GitHub Actions with Google Service Account (GSA) credentials for proper authentication and pushing to the required GCR endpoints.
4. Rotate docker credentials once everything is working as expected

What alternatives are there?

[amishas157]

For the current Build docker image workflows in stellar-dbt, stellar-etl, stellar-etl-internal, can you update location to be GCR instead of Dockerhub?