Only exclude .git for bundles, not all hidden paths

[jeremybeard]

Description

This change fixes a bug where all hidden files were being removed from the DAG bundle, which excluded important files such as .airflowignore. Instead, only the .git directory is excluded, which was the intention behind the original hidden files change.

🧪 Functional Testing

• Unit tests updated
• Manually tested with --verbosity debug which shows .airflowignore being included and .git files being excluded.

📸 Screenshots

📋 Checklist

• [x] Rebased from the main (or release if patching) branch (before testing)
• [x] Ran make test before taking out of draft
• [x] Ran make lint before taking out of draft
• [x] Added/updated applicable tests
• [x] Tested against Astro-API (if necessary).
• [ ] Tested against Houston-API and Astronomer (if necessary).
• [ ] Communicated to/tagged owners of respective clients potentially impacted by these changes.
• [ ] Updated any related documentation