#76958 reported an iOS App Store validation error because of an errant Runner.app/Frameworks/.last_build_id file in the archive bundle. That file is generated by the assemble build system to track when targets can be skipped. That particular issue will be fixed with #77007 but it would be nice to support the bundle directories as assemble output directories.

1. Validate making .last_build_id a hidden file avoids validation issues.
2. If so, make .last_build_id hidden when written by setting the com.apple.FinderInfo extended attribute to 32. The com.apple.FinderInfo attribute requires a 32-byte block, so it looks like:

xattr -wx com.apple.FinderInfo 2020202020202020401000000000000000000000000000000000000000000000 .last_build_id

See man getattrlist ATTR_CMN_FNDRINFO for info.