wip(ci): switch to Sparkle Motion board repo branch

Author: tyeth

.github/workflows/build-clang-doxy.yml

@@ -429,6 +429,7 @@ jobs:
         with:
           repository: adafruit/Wippersnapper_Boards
           path: ws-boards
+          ref: add-sparkle-motion
       - name: Install CI-Arduino
         run: bash ci/actions_install.sh
       - name: Install extra Arduino libraries