Update actions/cache from v2 to v4

Fix deprecated actions/cache version to avoid workflow interruptions.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: JustWalters

.github/workflows/package.yaml

@@ -17,7 +17,7 @@ jobs:
         run: |
           echo "::set-output name=version::$(node --version)"
       - name: Cache node_modules
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         id: cache-node-modules
         with:
           path: node_modules