Fix possible undefined access in error test assertions

Updated the test to safely handle potential undefined values in the stacktrace frames. This prevents runtime errors during test execution and ensures robust validation of error handling logic.

Author: cod1k

dev-packages/e2e-tests/test-applications/node-express/tests/errors.test.ts

@@ -37,6 +37,6 @@ test('Should record caught exceptions with local variable', async ({ baseURL })
 
   const errorEvent = await errorEventPromise;
 
-  const frames = errorEvent.exception?.values?.[0].stacktrace?.frames;
-  expect(frames?.[frames.length - 1].vars?.randomVariableToRecord).toBeDefined();
+  const frames = errorEvent.exception?.values?.[0]?.stacktrace?.frames;
+  expect(frames?.[frames.length - 1]?.vars?.randomVariableToRecord).toBeDefined();
 });