fix(integ-runner): don't throw error if tests pass (#20511)

If you run `integ-runner --update-on-failed` and the test succeeds, then
the cli should not return an exit code.

re #20384


----

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### Adding new Unconventional Dependencies:

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### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/master/INTEGRATION_TESTS.md)?
	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?

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

Author: corymhall

packages/@aws-cdk/integ-runner/lib/cli.ts

@@ -49,9 +49,10 @@ async function main() {
 
   let failedSnapshots: IntegTestWorkerConfig[] = [];
   if (argv['max-workers'] < testRegions.length * (profiles ?? [1]).length) {
-    logger.warning('You are attempting to run %s tests in parallel, but only have %s workers. Not all of your profiles+regions will be utilized', argv.profiles*argv['parallel-regions'], argv['max-workers']);
+    logger.warning('You are attempting to run %s tests in parallel, but only have %s workers. Not all of your profiles+regions will be utilized', argv.profiles * argv['parallel-regions'], argv['max-workers']);
   }
 
+  let testsSucceeded = false;
   try {
     if (argv.list) {
       const tests = await new IntegrationTests(argv.directory).fromCliArgs();
@@ -99,6 +100,8 @@ async function main() {
         verbose: argv.verbose,
         updateWorkflow: !argv['disable-update-workflow'],
       });
+      testsSucceeded = success;
+
 
       if (argv.clean === false) {
         logger.warning('Not cleaning up stacks since "--no-clean" was used');
@@ -125,7 +128,9 @@ async function main() {
     if (!runUpdateOnFailed) {
       message = 'To re-run failed tests run: yarn integ-runner --update-on-failed';
     }
-    throw new Error(`Some snapshot tests failed!\n${message}`);
+    if (!testsSucceeded) {
+      throw new Error(`Some tests failed!\n${message}`);
+    }
   }
 
 }