refactor(typing): Remove now-unused isinstance_or_issubclass overloads

[dangotbanned]

What type of PR is this? (check all applicable)

• 💾 Refactor
• ✨ Feature
• 🐛 Bug Fix
• 🔧 Optimization
• 📝 Documentation
• ✅ Test
• 🐳 Other

Related issues

• Full revert of chore(typing): More isinstance_or_issubclass overloads #2731
• Not needed since feat: Add DType.base_type #2969

Checklist

• Code follows style guide (ruff)
• Tests added
• Documented the changes

If you have comments or can explain your changes, please do so below

Now, we only have 1 case which uses the 2x @overload(s).
I'm keeping the 3x as well for now, just in case that changes 🙂

[FBruzzesi]

I will never complain on these simplifications. As a general comment, the typing for this function seems a bit hard to maintain and not very scalable 🥲

[dangotbanned]

As a general comment, the typing for this function seems a bit hard to maintain and not very scalable

Couldn't agree more tbf 😂

(#2371) was really just trying to add typing to a complex situation we were already in

If we make some progress on (#2486), then we may be able to remove the need for it entirely 🙏