Update actions/cache action to v6 (#775)

Author: renovate[bot]

.github/workflows/build.yml

@@ -211,7 +211,7 @@ jobs:
           jq . infection.json5
 
       - name: "Cache Result cache"
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: ./tmp
           key: "result-cache-v1-${{ matrix.php-version }}-${{ github.run_id }}"