ci: Bump Meson version to 0.60.1 on macOS
This is an attempt to fix a persistent error on the macOS CI:
Objective-C compiler for the host machine: cc (clang 10.0.0)
Objective-C linker for the host machine: APPLE ld 409.12
WARNING: No include directory found parsing "cc -xobjc -E -v -" output
meson.build:761:2: ERROR: Fatal warnings enabled, aborting
For example, seen on https://gitlab.gnome.org/GNOME/glib/-/jobs/1618966.
Signed-off-by: Philip Withnall pwithnall@endlessos.org