cleanup deploy.hcl sha

[zreigz]

Summary

plural destroy should not delete deploy.hcl for each app, just clean up the sha field in this file

Labels

Test Plan

Checklist

• [ ] If required, I have updated the Plural documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] I have added a meaningful title and summary to convey the impact of this PR to a user.
• [ ] I have added relevant labels to this PR to help with categorization for release notes.