chore: fix unstable log on replay-logs-chronological-order snap-test (#347)

### TL;DR

Added a delay before the main process ends to ensure logs are properly flushed to stdout.

### What changed?

- Imported the `scheduler` from `node:timers/promises`
- Added a 100ms delay using `scheduler.wait(100)` before the main process ends
- Added a comment explaining that this delay ensures logs from echo.js are flushed to stdout before the main process terminates

### How to test?

Run the replay-logs-chronological-order snap test and verify that all logs from the child processes are properly captured in the output.

### Why make this change?

Without this delay, the main process might terminate before all child process logs are properly flushed to stdout, potentially causing logs to be missed or appear out of order in test results. This change ensures more reliable and consistent test output.

Author: fengmk2

packages/cli/snap-tests/replay-logs-chronological-order/build.js

@@ -1,4 +1,5 @@
 import { spawn } from 'node:child_process';
+import { scheduler } from 'node:timers/promises';
 
 async function main() {
   const commands = [
@@ -42,6 +43,8 @@ async function main() {
     await exec(...command);
   }
 
+  // Wait for 100ms to ensure all child process output streams (e.g., from echo.js via console.warn to stderr) are fully flushed to the parent process before exiting.
+  await scheduler.wait(100);
   console.log('[build.js] main process end');
 }