A repo with no packageManager field got the newest pnpm through Corepack.
Several repos pin pnpm in their own workflows instead. Add a pnpm-version
input to node-pr and renovate-autoupdate and activate it with corepack.
Add a reusable workflow that installs without changing the lockfile and
runs lint, typecheck, test and build, skipping scripts that do not exist.
It follows go-pr: a push to a branch with an open PR skips the duplicate
run, and stale runs are cancelled.
lukaszraczylo
