chore: remove unnecessary `declare module` block in typings

[JounQin]

The typings are in its own package, so declare module is redundant.

[JounQin]

ping @wojtekmaj

[wojtekmaj]

In this case, what about entry.nostyle.d.ts?

[JounQin]

In this case, what about entry.nostyle.d.ts?

@wojtekmaj

It is not types in package.json, or the same dir as dist/entry.nostyle .js, so its declare module is required, and this PR will not break that.

Personally, I would prefer to have entry.nostyle.d.ts at dist/entry.nostyle.d.ts, then no declare module is required.