Take ClientT inside of the ErrorFunc

[PythonCoderAS]

Summary

Currently, using self.tree.error inside of a Bot or another subclass with proper type checking enabled via Pylance:

from discord.ext.commands import Bot
from discord import Interaction

class MyBot(Bot):
    def __init__(self, *a, **kw):
        super().__init__(*a, **kw)

        @self.tree.error
        async def tree_error(interaction: Interaction[MyBot], error: Exception):
            print("Error!")

Error:

Argument of type "(interaction: Interaction[MyBot], error: Exception) -> Coroutine[Any, Any, None]" cannot be assigned to parameter "coro" of type "ErrorFunc" in function "error"
  Type "(interaction: Interaction[MyBot], error: Exception) -> Coroutine[Any, Any, None]" is not assignable to type "ErrorFunc"
    Parameter 1: type "Interaction[Client]" is incompatible with type "Interaction[MyBot]"
      "Interaction[Client]" is not assignable to "Interaction[MyBot]"
        Type parameter "ClientT@Interaction" is covariant, but "Client" is not a subtype of "MyBot"
          "Client" is not assignable to "MyBot"Pylance[reportArgumentType](https://github.com/microsoft/pyright/blob/main/docs/configuration.md#reportArgumentType)

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)