Optionally skipping schema based codegen on startup

[StepanMynarik]

Describe the feature

Open Fetch does codegen on every startup and now also on every hot reload.
We have a huge schema file that changes like once a year. The codegen takes 11 seconds.

Would it be possible to add some option to skip the codegen on startup?
It would be a nice DX improvement.

Additional information

• Would you be willing to help implement this feature?

Final checks

• Read the contribution guide.
• Check existing discussions and issues.