v0.2.1-alpha: Switch from removed `macos-11` runners to `macos-latest` with Xcode 16.1

The `macos-11` runners are no longer hosted by GitHub as this OS version
is too old.  Likewise Xcode 13.2.1 is no longer available, the lowest
supported version appears to be `15.0`.

v0.2.0

Release xbuild 0.2.0

v0.1.0+4

Create binary xbuild releases.

v0.1.0+3

Update sdk.

v0.1.0+2

Repackage ndk.

v0.1.0+1

Fix macos/ios sdks.