CI: MacOS update causes build failure

Example: https://gitlab.haskell.org/ghc/ghc/-/jobs/1811344

This affected https://gitlab.haskell.org/admin/runners/706#/ and https://gitlab.haskell.org/admin/runners/705#/

@angerman reports:

When you run m4, it tells you "requesting installation of command line developer tools", you then get the popup, it installs the CLT.

If you run m4 again, the whole process starts all over again.

Command line: sh configure --enable-shared=no --with-pic=yes --host=aarch64-apple-darwin --build=aarch64-apple-darwin
===> Command failed with error code: 1
configure: error: No usable m4 in $PATH or /usr/5bin (see config.log for reasons).