chore: use pnp linker in validate-yarn-cache step

.github/workflows/ci.yml

@@ -24,6 +24,7 @@ jobs:
         if: steps.yarn-cache.outputs.cache-hit != 'true'
         env:
           YARN_ENABLE_SCRIPTS: false # disable post-install scripts
+          YARN_NODE_LINKER: pnp # use pnp linker for better performance: it meant to update yarn cache only
         run: |
           yarn install --immutable