Pin max clang version

Author: dstansby

.github/workflows/ci-osx.yaml

@@ -38,7 +38,7 @@ jobs:
         shell: "bash -l {0}"
         run: >
           conda create -n env
-          c-compiler cxx-compiler 'clang>=12.0.1'
+          c-compiler cxx-compiler 'clang>=12.0.1,<17'
           python=${{matrix.python-version}} wheel pip
 
       - name: Show info about `env` environment