libtbx supported_mtype failure on M1 Mac

[huwjenkins]

DIALS v3-11-2 refuses to install on my M1 Mac. v3-11-1 worked fine. The issue is in libtx so reporting here. In this version os.uname() here:

https://github.com/cctbx/cctbx_project/blob/0caf7ea69b90f7fd3f6fa5374ed2aaf3c806fb58/libtbx/auto_build/installer_utils.py#L176 returns:

posix.uname_result(sysname='Darwin', nodename='xxx.xxx', release='21.6.0', version='Darwin Kernel Version 21.6.0: Mon Aug 22 20:19:52 PDT 2022; root:xnu-8020.140.49~2/RELEASE_ARM64_T6000', machine='arm64')

i.e. machine='arm64' and so mtype is set to mac-intel-osx-x86_64-10.9 rather than mac-intel-osx-x86_64 which is not in the list here:

https://github.com/cctbx/cctbx_project/blob/0caf7ea69b90f7fd3f6fa5374ed2aaf3c806fb58/libtbx/auto_build/install_distribution.py#L115-L121

Error is:

Traceback (most recent call last):
  File "/Users/huw/Downloads/dials-installer/./bin/install.py", line 311, in <module>
    installer(sys.argv[1:]).install()
  File "/Users/huw/Downloads/dials-installer/lib/libtbx/auto_build/install_distribution.py", line 188, in install
    self.basic_setup()
  File "/Users/huw/Downloads/dials-installer/lib/libtbx/auto_build/install_distribution.py", line 219, in basic_setup
    raise InstallerError("""
InstallerError:
  mac-intel-osx-x86_64-10.9 is not a supported platform, installation aborted
    use the --try-unsupported option to attempt installation on this platform
    use the --no-gui option for a core DIALS installation