Add workflow + rootless build config

[L1ghtmann]

Changes:

• Bumped deployment target to 11.0 as ArgumentParser requires >= 11.0
• Added rootless scheme control and build script
• Added workflow to build both rootful (iphoneos-arm) and rootless (iphoneos-arm64) schemes

Notes:

• Tested briefly on my iP7 iOS 15.4.1 palera1n and it seems to function fine as-is without code modifications
• Packix is now archived, so if you end up publishing builds in the future you'll likely have to switch over to Havoc (Packix's successor) or use GitHub Releases/Nightly