Fall back to raw test results if the TAB API is down (#7957)

Author: jacebrowning

.github/ci-cd-scripts/upload-results.sh

@@ -47,4 +47,8 @@ curl --silent --request POST \
   ${TAB_API_URL}/api/share
 echo
 
-grep --quiet '"block": false' test-results/tab.json
+if [ -f "test-results/tab.json" ]; then
+  grep --quiet '"block": false' test-results/tab.json
+else
+  grep --quiet 'failures="0"' test-results/junit.xml
+fi