fix(ci): unlink gcc after installing netcdf-fortran

Author: wpbonelli

.github/actions/test-extended/action.yml

@@ -20,6 +20,13 @@ runs:
       shell: bash
       run: |
         brew install netcdf-fortran libevent
+        # netcdf-fortran pulls in Homebrew's unversioned (latest) gcc as a
+        # dependency, symlinking an unpinned gfortran/gcc/g++ into
+        # /opt/homebrew/bin, which precedes /usr/local/bin on PATH and would
+        # otherwise shadow the version setup-fortran pins below.
+        if brew list --formula gcc &>/dev/null; then
+          brew unlink gcc
+        fi
         nc-config --all
         nf-config --all