♻️ Upgrade to GPT4o

[bradystroud]

Keep GPT 3.5 as the signed out model.

Change the signed in model from GPT 4 to GPTo (faster + cheaper)

### Tasks
- [ ] When you sign in you can use GPT 4o
- [ ] Consider refactoring code to make this easy - There will frequently be new models released, and we should make it as easy as possible to update RulesGPT to support them
- [ ] Alternatively, document the process so the changes are easy for next time

[jernejk]

@bradystroud, can we add GPT-4o-mini, o1 and o1-mini as well?