[Feature Request] Configure Terraform Tests to accept PRs from forks

[jlacefie]

Is your feature request related to a problem? Please describe.

The Terraform Provider Acceptance Tests use secrets for authentication. GitHub Actions does not pass secrets to workflows triggered by pull requests from forks or from outside contributors by design, as a security precaution. The end result is that PRs from non Temporal contributors receive failed tests.

Describe the solution you'd like

There are a few options to resolve this issue. The end goal is to support a full, automated test of all resources using an API Key in a way that is secure and which doesn't expose the API Key secret in an undesired way.