Cleanup bundle files before checking the rebuild

Signed-off-by: Julius Härtl <jus@bitgrid.net>

.github/workflows/node.yml

@@ -24,6 +24,7 @@ jobs:
         node-version: ${{ matrix.node-version }}
     - name: Install dependencies & build
       run: |
+        make clean
         npm ci
         npm run build --if-present
     - name: Check webpack build changes