test only m4 for acep

Author: ladyada

.github/workflows/githubci.yml

@@ -19,8 +19,14 @@ jobs:
     - name: pre-install
       run: bash ci/actions_install.sh
 
+    # manually install SDFat
+    - name: extra libraries
+      run: |
+        git clone --quiet https://github.com/adafruit/SdFat.git /home/runner/Arduino/libraries/SdFat
+
+
     - name: test platforms
-      run: python3 ci/build_platform.py main_platforms cpb cpx
+      run: python3 ci/build_platform.py main_platforms metro_m4_tinyusb cpb cpx
 
     - name: clang
       run: python3 ci/run-clang-format.py -e "ci/*" -e "bin/*" -r .