Swap C6 to DIO to test bug

Author: tyeth

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

@@ -266,7 +266,7 @@ jobs:
         with:
           repository: adafruit/ci-arduino
           path: ci
-          ref: ci-wippersnapper
+          ref: ci-wippersnapper-c6-dio
       - name: Checkout Board Definitions
         uses: actions/checkout@v4
         with: