more .syncignore fixup

[mhdawson]

Summary

• avoid addition of receipts.sh since not being used for ubi stack

Use Cases

Checklist

• [x] I have viewed, signed, and submitted the Contributor License Agreement.
• [x] I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• [x] I have added an integration test, if necessary.
• [x] I have reviewed the styleguide for guidance on my code quality.
• [x] I'm happy with the commit history on this PR (I have rebased/squashed as needed).

[mhdawson]

I think https://github.com/paketo-community/ubi-base-stack/pull/14 needs to land for the CI in this PR to pass.

[sophiewigmore]

added these changes to the github-config PR