Install browsers and set CHROME_BIN in the gitea workflow

.gitea/workflows/test.yaml

@@ -9,10 +9,10 @@ jobs:
         run: |
           apt-get update
           apt-get install -yq --no-install-suggests --no-install-recommends \
-          xauth xvfb
+          xauth xvfb chromium firefox-esr
       - name: Check out repository code
         uses: actions/checkout@v3
       - name: Install
         run: npm install
       - name: Run tests
-        run: npm test
+        run: CHROME_BIN=/usr/bin/chromium npm test