Use partial discovery by default during local development

[innocenzi]

Since we recommend running discovery:generate on post-autoload-dump, I think the partial discovery should be enabled by default in local. We already enable full discovery in production unless DISCOVERY_CACHE is defined.

What do we think @brendt?

[brendt]

Yes, I actually thought this was already the case 🫣

Discovery cache should only be completely off when debugging framework related issues.