Guard against edge case NPE in async tests

Author: Brian Vaughn

packages/react-devtools-shared/src/backend/profilingHooks.js

@@ -639,13 +639,17 @@ export function createProfilingHooks({
           suspenseEvent.duration = getRelativeTime() - suspenseEvent.timestamp;
           suspenseEvent.resolution = 'resolved';
 
-          markAndClear(`--suspense-resolved-${id}-${componentName}`);
+          if (supportsUserTimingV3) {
+            markAndClear(`--suspense-resolved-${id}-${componentName}`);
+          }
         },
         () => {
           suspenseEvent.duration = getRelativeTime() - suspenseEvent.timestamp;
           suspenseEvent.resolution = 'rejected';
 
-          markAndClear(`--suspense-rejected-${id}-${componentName}`);
+          if (supportsUserTimingV3) {
+            markAndClear(`--suspense-rejected-${id}-${componentName}`);
+          }
         },
       );
     }