fix: pnpm via npm -g — Node 25 distributions no longer bundle corepack

action.yml

@@ -1,5 +1,5 @@
 name: better-setup-node
-description: Install a pinned musl Node from the official unofficial-builds (glibc builds cannot exec on musl runners) and optionally activate a pinned pnpm via corepack.
+description: Install a pinned musl Node from the official unofficial-builds (glibc builds cannot exec on musl runners) and optionally install a pinned pnpm via npm (Node 25 dropped bundled corepack).
 inputs:
   node-version:
     description: Exact Node version to install (e.g. 22.14.0).
@@ -30,7 +30,7 @@ runs:
         fi
         node --version
         if [ -n "$pv" ]; then
-          corepack enable
-          corepack prepare "pnpm@${pv}" --activate
+          # Node 25 dropped bundled corepack; npm ships with every distribution.
+          npm install -g "pnpm@${pv}"
           pnpm --version
         fi