Pipeline: Fix flakiness on Pa11y CI (#39358)

* Pipeline: Add wait prop into pa11y configuration for all the pages

* Pa11y: Use e2e instance to generate html report local environment

* Pipeline: use pa11y-ci hash commit

* Pipeline: Update Pa11y thresholds

* Update package.json

* Update yarn.lock

Co-authored-by: Leon Sorokin <leeoniya@gmail.com>

scripts/generate-a11y-report.sh

@@ -15,9 +15,18 @@ if [ -d "$report" ] ; then
     rm -R "$report"
 fi
 
-# Run accessibility command
-yarn wait-on http://localhost:3000
 
+# Run e2e grafana instance 
+
+if [ "$BASE_URL" != "" ]; then
+    echo -e "BASE_URL set, skipping starting server"
+else
+  # Start it in the background
+  ./e2e/start-server > e2e/server.log &
+  ./e2e/wait-for-grafana
+fi
+
+# Run accessibility command
 yarn run -s test:accessibility --json > pa11y-ci-results.json
 
 # Generate HTML report