test: example-docker use action from branch (#1055)

Author: MikeMcC399

.github/workflows/example-docker.yml

@@ -19,7 +19,9 @@ jobs:
       options: --user 1001
     steps:
       - uses: actions/checkout@v4
-      - uses: cypress-io/github-action@v6
+      # replace with the following for regular use:
+      # uses: cypress-io/github-action@v6
+      - uses: ./
         with:
           working-directory: examples/basic
           browser: ${{ matrix.browser }}