feat: use watcher for restart only in HMR mode

[kerwanp]

🔗 Linked issue

❓ Type of change

• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[kerwanp]

I struggled for way too long trying to understand why the child process was hanging even in case of syntax error.
As I was testing in a real application I had Redis (cache, transmit and queue) which by default uses lazyConnect: false meaning that the connection is opened before the application enters in the starting phase and is not closed and keep the process hanging.

This is unrelated to this PR but I wanted to note that.