chore(deps)!: update terraform googlecloudplatform/lb-http/google to v12

BREAKING CHANGE: Remove the `use_ssl_certificates` variable as the load
balancer module no longer accepts it.

Update tests and examples to use a more recent version (v23) of the SQL
module to resolve provider version conflicts.

Modify tests to only verify Google provider versions >= 6 as this is the
minimum version supported by Google's load balancer module.