Add test step for starting a local cluster with default --log-dir

The verify_cli_errors job is already using macos-12, so the
current behaviour *should* be to fail with error - unless `/usr`
is indeed writable on a fresh x86_64 install.

If it fails, we need to change the macos `get_log_directory()` impl.

.github/workflows/ci_mac.yaml

@@ -248,6 +248,11 @@ jobs:
           fluvio cluster start --local --develop --skip-checks --log-dir "${log_dir}" 2> >(tee $stderr >&2)
           [ $? -eq 0 ] && { echo "Expected nonzero exit code, got $?"; exit 2; }
           grep -qF "${log_dir}" $stderr || { echo "Expected to find '${log_dir}' in stderr"; exit 3; }
+      - name: Start local fluvio cluster with default --log-dir
+        timeout-minutes: 5
+        run: |
+          echo "Starting cluster with default '--log-dir'"
+          fluvio cluster start --local --develop --skip-checks
 
  # same as in ci.yaml except no aa64
   build_image: