fix: reinstall a cached package manager when its recorded bins are missing

[abappi19]

Fixes #901

• Corepack <=0.34.4 caches pnpm 12 with bin: ./bin/pnpm.cjs, a file pnpm 12 doesn't ship. Later releases reuse that record as is and fail with Cannot find module.
• installVersion now checks the recorded bins before reusing a cache entry. If none of them exist, it removes the folder and installs again, which writes a fresh .corepack.
• It only reinstalls when every recorded bin is missing. Some packages don't ship every bin in the config (e.g. old pnpm without pnpx.js), so "any missing" would download again on every run.

Testing:

• New test in tests/main.test.ts points a cached record at missing files and expects a reinstall. It fails without the change. tests/nocks.db is unchanged.
• yarn test, yarn typecheck and yarn lint pass.
• Repro from Cannot find module .../bin/pnpm.cjs after upgrading from Corepack <=0.34.4 with pnpm 12 cached #901 passes with this build. I also ran Corepack 0.29.4 to 0.36.0 against pnpm 10, 11 and 12: every stale pnpm 12 entry fails on released versions and works with this change.

AI disclosure: I used a coding agent to help write the change and the test. I reproduced the bug, reviewed the diff and ran the tests myself.