Restrict Nightly Releases Workflow to Main Repository

[cedricrabarijohn]

The current nightly releases workflow (.github/workflows/nightly-releases.yml) should be restricted to run only in the main repository (wpengine/faustjs) and not in any forks. This is to prevent unnecessary executions in forked repositories.

[ahuseyn]

Thank you @cedricrabarijohn for letting us know. #2105 should fix this issue.

[cedricrabarijohn]

thanks @ahuseyn