fix(packaging): Adjust the exclude list to package the composer autol…

[nickvergessen]

…oader

From release todo:

• Create a test package and check if a new development file needs to be added to the packaging exclude list in Makefile

  make appstore

That showed composer/autoloader.php, but that linked to dead files

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included
• 📘 API documentation in docs/ has been updated or is not required
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required
• 🔖 Capability is added or not needed