chore: specify pnpm version in package json

[bartektelec]

specifies the pnpm version to use when contributing
enables contributors to easily switch to the correct version using corepack

update:
looks like the codesandbox demo runs of pnpm@7.26.3, do we want to lock the pnpm version to the major? pnpm@^7.0.0

[kettanaito]

@bartektelec, we need to lock PNPM version to the one used on the CI to make sure builds are passing (lock mismatches due to PNPM version mismatches throw):

msw/.github/workflows/ci.yml

Lines 24 to 26 in e87e00b

	- uses: pnpm/action-setup@v2
	with:
	version: 7.12

If the sandbox is using an older/newer version, it likely has to be pinned to but we don't have to solve it. The need to have a stable version is to:

• Make sure it's signaled for new contributors cloning the project locally;
• Make sure new contributors don't commit the lockfile generated on a different PNPM version, breaking the build.

[kettanaito]

Thanks for opening this! I left a few suggestions on how to make a new contributing experience a bit more streamlined in regards to the correct PNPM version. Let me know what you think.

[kettanaito]

This looks fantastic! Thank you for improving the experience, @bartektelec! 👏

[kettanaito]

Welcome to contributors! 🎉

[kettanaito]

Released: v1.2.4 🎉

This has been released in v1.2.4!

• 📄 Release notes
• 📦 npm package

Make sure to always update to the latest version (npm i msw@latest) to get the newest features and bug fixes.

---

Predictable release automation by @ossjs/release.

[auskast]

Specifying the pnpm version in the engines field causes consumers of the package not running the specified pnpm version to not be able to install the library. The packageManager field should be sufficient for development purposes.

Error message:

 ERR_PNPM_UNSUPPORTED_ENGINE  Unsupported environment (bad pnpm and/or Node.js version)

This error happened while installing a direct dependency of /tmp/renovate/repos/<redacted>

Your pnpm version is incompatible with "registry.npmjs.org/msw/1.2.4".

Expected version: ~7.12
Got: 8.6.12

This is happening because the package's manifest has an engines.pnpm field specified.
To fix this issue, install the required pnpm version globally.

To install the latest version of pnpm, run "pnpm i -g pnpm".
To check your pnpm version, run "pnpm -v".

[kettanaito]

Thanks for reporting this, @auskast. I've addressed this issue in #1713. The fix will be automatically released in the upcoming days.