[Bug]: Emily codegen do not work if json specs are invalid

[MCJOHN974]

Chore - Make Emily codegen do not rely on current files.

1. Description

If json specs are invalid, sometimes Emily codegen bail on this specs instead of trying to rebuild them. However, this files are autogenerated and shouldn't be touched manually, so Emily codegen should try to rebuild json specs from scratch.

2. Why It's Necessary

It can be painful sometimes to ask the codegen to do codegen because of this

3. Execution Checklist

• make build always fully proceed with whole Emily codegen pipeline from scratch (handwritten rust -> json specs -> generated rust)