Performance tips docs page

[samuelcolvin]

Page in the docs with tips on using pydantic in the most performant way.

Should start with a big notice saying something like "In most cases pydantic won't be your bottle neck, only follow this if you're sure it's necessary blah blah blah".

1. Use model_validate_json() not model_validate(json.loads(...)) (👀 FastAPI)
2. TypeAdapter instantiated once - generally avoid constructing validators and serializers more than necessary
3. Sequence vs list/tuple - Mapping vs dict
4. Don't do validation when you don't have to - use Any to keep the value unchanged
5. generally avoid recording extra information via subclasses of primatives
6. Use tagged union, not union
7. Use Literal not Enum (not sure how big this effect is)
8. use TypedDict over nested models
9. Avoid wrap validators if you really care about performance

Anything else?

Selected Assignee: @Kludex

[Burnsedia]

Another thing you can do I do the simple calculations first, only to the complicated once when you have to. another is object pooling arrays and time slicing.

[sydney-runkle]

Looks like this should have been closed by @Kludex's #7567 PR. Closing now, as the minimum reqs for this page have been met. I think we should open a new issue with new requests for this page if/when they're desired.