GCP Batch Executor Functional Tests

[AlejandroEsquivel]

Acceptance Criteria

• Implement the GCP Executor terraform script in the terraform repo under the folder with the same name as the executor repo. Refer to this TDD for the terraform script.
• Ensure that the terraform script provides the necessary outputs to configure the executor. One can refer to the terraform scripts of the other plugins as well as the functional tests workflow to get a good understanding of what's required.
• Configure OIDC between GitHub actions and Google
• Add a new entry to the test matrix in the terraform repo to include this plugin
• Test the workflow by adding a on pull_request trigger, disabling the other executor plugins in the test matrix and specifying the working branch in the test matrix
• Ensure the functional test passes