actions: allow invoke only on local execution while TFC adds support

[liamcervante]

This PR just returns an error early if a user tries to invoke actions with a cloud backend. TFC hasn't been updated yet, and Terraform crashes if this is attempted. With this we just get an error message instead of a crash, and we can remove this once TFC is up to date.

Target Release

1.14.x

Rollback Plan

• If a change needs to be reverted, we will roll out an update to the code within 7 days.

Changes to Security Controls

Are there any changes to security controls (access controls, encryption, logging) in this pull request? If so, explain.

CHANGELOG entry

• This change is user-facing and I added a changelog entry.
• This change is not user-facing.

[github-actions]

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