Update index.ts of jest addon to make withTests type generic

[CodeByAlex]

Issue: #8058

What I did

Update index.ts of jest addon to make withTests type generic

How to test

• Is this testable with Jest or Chromatic screenshots? no
• Does this need a new example in the kitchen sink apps? no
• Does this need an update to the documentation? no

If your answer is yes to any of these, please make sure to include it in your PR.

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[shilman]

@CodeByAlex how do I test this?

[kroeder]

The error that appears in the related issue is Argument of type 'DecoratorFunction<unknown>' is not assignable to parameter of type 'StoryDecorator'.

Making it any fixes the issue I guess. But maybe it should have been of type StoryDecorator in the first place? Or are there other use-cases?

[CodeByAlex]

Yeah, thats right @kroeder - I was thinking that there may be other use cases and didn't want to cause the same issues that we saw with making knobs strict. If you think it would be fine setting the type to StoryDecorator, I can change it to that.

[kroeder]

We could add tests for all possible inputs. That's the easiest way to ensure typings are correct I guess
But if any fixes the issue we can do that and raise another issue with "improve typings for addon-jest"