[LOTC-2294] bump ci cache action to v4

Author: erikjmiller

.github/workflows/pdf417.yml

@@ -40,7 +40,7 @@ jobs:
 
       - name: Retrieve Cached Dependencies
         id: mix-cache
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: |
             ./deps