test(node): Increase timeout in OnUncaughtException test scripts to fix flaky CI

[JPeer264]

closes #20796
closes JS-2432

closes #20698
closes JS-2368

closes #20689
closes JS-2363

closes #20974
closes JS-2531

closes #20798
closes JS-2434

closes #20792
closes JS-2430

closes #20788
closes JS-2428

The 500ms timeout was too short - when network conditions cause the SDK's client.close() to take longer than 500ms (it has a 2000ms timeout), the watchdog fires first and the test fails with "I'm alive!" in stdout.

This can be reproduced with the following script:

const Sentry = require('@sentry/node');

Sentry.init({
  dsn: 'https://public@10.255.255.1/1337',  // Unreachable IP - simulates slow network
});

setTimeout(() => {
  process.stdout.write("I'm alive!");
  process.exit(0);
}, 3000);  // Was 500ms before the fix

throw new Error('Test');

[linear-code]

JS-2432

JS-2368

JS-2363

JS-2531

JS-2434

JS-2430

JS-2428