chore(deps): update actions/cache action to v5

Author: renovate[bot]

.github/workflows/build.yml

@@ -27,7 +27,7 @@ jobs:
     - uses: actions/checkout@v6
 
     - name: Cache sbt
-      uses: actions/cache@v4
+      uses: actions/cache@v5
       with:
         path: |
           ~/.sbt

.github/workflows/version-policy-check.yml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v6
 
       - name: Cache sbt
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.sbt