fix: configure pa11y-ci for GitHub Actions (Chromium --no-sandbox)

Author: LauraLangdon

.github/workflows/deploy.yml

@@ -34,7 +34,8 @@ jobs:
       - run: npx linkinator ./_build/html/
 
       - name: Accessibility check
-        # pa11y-ci needs a running server to crawl the built site
+        # pa11y-ci needs a running server to crawl the built site.
+        # Chromium requires --no-sandbox on GitHub Actions runners (see .pa11yci).
         run: |
           npx serve _build/html -p 4117 &
           SERVER_PID=$!

.pa11yci

@@ -1,6 +1,9 @@
 {
   "defaults": {
     "standard": "WCAG2AA",
-    "timeout": 15000
+    "timeout": 15000,
+    "chromeLaunchConfig": {
+      "args": ["--no-sandbox"]
+    }
   }
 }