✨ Increase number_of_types to 5 to support longer select queries

[GiorgioPorgio]

I am trying to write a select statement that selects 5 different SQLModel children. However I get a type error as the overloads for select are limited to 4.

I am aware there is a #839 that adds typing for select for arbitrary length :) Sadly that one does not work and will break consumers.
I resolved it's conflicts and tried it on my project and then realised that the Python type system cannot maintain specific types of variadic generic arguments without specifying them explicitly. I can provide an example if you want :)

I presume this is also the reason we went with the templating approach in the first place.

Increasing to 6+ causes mypy to hang, so I chose 5 :)

Resolves #271 (comment)

Thank you very much for your time and working on OSS!

PS: I had another PR where I fixed the conflicts of variadic typing before realising this could not work with Python's type system - so I closed it to ensure it wouldn't accidentally get merged

[GiorgioPorgio]

Everything in this file is autogenerated by running the script (*_*)