[Refactor] Make @tensorclass work properly with pyright

[Mxbonn]

Description

Describe your changes in detail.

Motivation and Context

@tensorclass() # works without typing issues
class MyClass:
    a = torch.Tensor
    b = torch.Tensor
    
@tensorclass # results in pyright typing issues and is arguably more commonly used than @tensorclass() with parentheses
class MyClass:
    a = torch.Tensor
    b = torch.Tensor

pyright: error:

Argument of type "type[MyClass]" cannot be assigned to parameter "autocast" of type "bool" in function "__new__"
  "type[type]" is not assignable to "type[bool]"Pylance[reportArgumentType](https://github.com/microsoft/pyright/blob/main/docs/configuration.md#reportArgumentType)

Types of changes

I looked at the @dataclass implementation and mimicked the behavior here. I'm no expert in typing.

• typing change

Potential breaking change:
Technically you could have used @tensordict the following:
@tensordict(<bool_for_autocast_without_using_the_keyword>)
or
@tensordict(<bool_for_autocast_without_using_the_keyword>, <bool_for_frozen_without_using_the_keyword>)

This will break now but I doubt any sane person uses it like that, cs.github.com did not show any such usage when I looked for it.

Checklist

Go over all the following points, and put an x in all the boxes that apply.
If you are unsure about any of these, don't hesitate to ask. We are here to help!

• I have read the CONTRIBUTION guide (required)

[facebook-github-bot]

Hi @Mxbonn!

Thank you for your pull request and welcome to our community.

Action Required

In order to merge any pull request (code, docs, etc.), we require contributors to sign our Contributor License Agreement, and we don't seem to have one on file for you.

Process

In order for us to review and merge your suggested changes, please sign at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need to sign the corporate CLA.

Once the CLA is signed, our tooling will perform checks and validations. Afterwards, the pull request will be tagged with CLA signed. The tagging process may take up to 1 hour after signing. Please give it that time before contacting us about it.

If you have received this in error or have any questions, please contact us at [email protected]. Thanks!

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Meta Open Source project. Thanks!