chore/msp: Upgrade Google providers to 7.31.0

[burmudar]

Stacks on #47, which first upgrades both Google providers to the final 6.x release.

This upgrades hashicorp/google and hashicorp/google-beta from 6.50.0 to 7.31.0 and regenerates their CDKTF Go bindings. Version 7.31 includes the fix for the spurious timeouts diff regression introduced alongside v7 identity support.

Rollout considerations

This PR only publishes generated bindings. After merge, sourcegraph/sourcegraph must update its generated-module dependencies and publish an sg msp build. The managed-services category lockfiles should then be upgraded and regenerated progressively: test, internal, then external.

Google provider v7 includes behavior changes that need review during live plans:

• google_project_service.disable_on_destroy no longer retains the old implicit true behavior when unset.
• Redis deletion protection defaults can block replacement or deletion unless explicitly disabled.
• Removed upstream resources should be checked against consumers before the Sourcegraph dependency update.

No live Terraform plans or applies were run as part of this bindings PR.

Test plan

• Regenerated Google and Google Beta bindings successfully.
• Parsed all generated JSON files.
• Ran go test ./dev/managedservicesplatform/... in sourcegraph/sourcegraph against the local 7.31 modules.
• Generated all environments from managed-services using an sg msp binary built against the local 7.31 modules.
• Ran Terraform 1.8.5 init -backend=false and validate for all five msp-testbed/robert stacks and representative external Cloud Run stacks from enterprise-portal/prod and releaseworker/prod.