always get pnpm to install through the node orb not just when a version is provided

Author: ramykl

src/commands/install.yml

@@ -85,10 +85,7 @@ steps:
               yarn-version: << parameters.package-manager-version >>
   - when:
       condition:
-        and:
-          - not:
-              equal: [ '', << parameters.package-manager-version >> ]
-          - equal: [ 'pnpm', << parameters.package-manager >> ]
+        equal: [ 'pnpm', << parameters.package-manager >> ]
       steps:
         - node/install:
             install-pnpm: true