fix(ci): let pnpm/action-setup read the version from packageManager

action-setup@v4 hard-fails when both the workflow 'version' input and
package.json's packageManager specify pnpm - every CI run since May died in
setup before running anything.

Author: TomerBenda

.github/workflows/ci.yml

@@ -17,9 +17,9 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      # pnpm version comes from package.json's "packageManager" field —
+      # specifying it here too makes action-setup@v4 fail on the mismatch.
       - uses: pnpm/action-setup@v4
-        with:
-          version: 9
 
       - uses: actions/setup-node@v4
         with: