package.json specifies pnpm >=9, which affects dependent packages

[jakebailey]

The package.json of this package has an engines field of pnpm >=9.

This actually declares to package managers "users installing this package with pnpm in their projects must be using pnpm >=9". As such, attempting to install this package in a pnpm v8 repo from the npm registry gives:

Your pnpm version is incompatible with "registry.npmjs.org/smol-toml/1.2.1".

Expected version: >= 9
Got: 8.10.4

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".

I don't think the intent of this field in this repo was to prevent installation of this package with pnpm 8, but rather to declare that this repo in particular is using pnpm v9.

Can this engine restriction be removed, and maybe replaced with some other kind of pnpm pinning, e.g. the packageManager field if desired?