Add ability to define export conditions per modules

[jiri-prokop-pb]

Summary

When migrating to MSW v2, we bumped into the problem described here: https://mswjs.io/docs/migrations/1.x-to-2.x/#cannot-find-module-mswnode-jsdom

Unfortunately the solution didn't work for us fully because we also have some other dependencies and the suggested solution was breaking another things.

For now we patched jest-runtime locally in our project to remove browser condition from customExportConditions only when resolving msw and @mswjs/interceptors modules and it works.

This PR is an attempt to make the logic configurable and more general.

It's my first contribution to Jest but I tried to update all relevant parts. The only thing I struggled with was testing. As far as I can see, customExportConditions are not tested right now and I wasn't sure how to prepare test env for it. If you want, I can look into it too but I'd welcome some guidance.

I hope this change make sense and could be accepted. I'm open to any feedback and adjustments.

Once it's in place, MSW could update their docs and hopefully it could help the community with adopting their new version in Jest.

Test plan

I created small demo repo: https://github.com/jiri-prokop-pb/jest-custom-export-conditions-demo-repo

You can test the logic by cloning it and running:

pnpm install
pnpm --filter main test

Tests should pass while respecting exports of different-exports sub-package and msw-related packages.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: jiri-prokop-pb / name: Jiří Prokop (f286c2e, e86d840, df2054b)

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