result of env.run is not inferring type, returning unknown

[chadxz]

What are you really trying to do?

I'm trying to test my activities using env.run and assert against the result.

Describe the bug

The return type of env.run is unknown when I would expect that it would be inferred from the activity.

Minimal Reproduction

https://codesandbox.io/p/devbox/l363c8

Environment/Versions

Macbook M2 Pro Sequoia 15.2
@temporal/testing 1.11.6

[chadxz]

I can work around the issue by passing explicit types to env.run, i.e.

        const result = await env.run<
          [UpdateCustomerRelationshipActivityInput],
          Nullable<UpdateCustomerRelationshipActivityResult>,
          typeof updateCustomerRelationship
        >(updateCustomerRelationship, {
          ...
        });

[chadxz]

@mjameswh here's a possible fix for this issue: chadxz@5884ef5

Main thing i'm not sure about is whether this would be considered a breaking change or not. I imagine if you were previously explicitly specifying the generic type parameters, a change like this may break you.

With the fix, you can see in the test suite that the return type is improved:

[chadxz]

Any thoughts on this? I'm happy to submit a PR, just want to make sure I take an appropriate approach.