fix(cli-integ): sporadic failures due to external causes (#897)

Some of our tests are failing sporadically due to factors out of our
control. In the past week, here are the failing tests:

<img width="1249" height="216" alt="Screenshot 2025-09-28 at 10 33
31 PM"
src="https://github.com/user-attachments/assets/c19c7d40-ef1f-4e7a-ad96-887a9f2e1ec2"
/>

Causes I observed so far:

- Prolonged docker build durations, most likely caused by network or CPU
pressure since we are running a lot of parallel processes.
- Lambda functions fail to create due to IAM eventual consistency
issues.

To mitigate this, add a global timeout for tests to execute 3 times
before finally failing.

> See
https://jestjs.io/docs/jest-object#jestretrytimesnumretries-options

---
By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license

Author: iliapolo

packages/@aws-cdk-testing/cli-integ/lib/integ-test.ts

@@ -35,6 +35,10 @@ export function integTest(
 ): void {
   const runner = shouldSkip(name) ? test.skip : test;
 
+  // we're quite a bit of sporadic failures due to environmental causes.
+  // lets retry 3 times to try and mitigate that.
+  jest.retryTimes(3);
+
   runner(name, async () => {
     const output = new MemoryStream();