update GitHub Cache action to 4.2.0

The cache action is stopping support for anything but the
very latest version. We need to update to 4.2.0 for the
cache to continue functioning.

actions/cache#1510

Author: pbalcer

.github/workflows/benchmarks-reusable.yml

@@ -232,7 +232,7 @@ jobs:
 
     - name: Upload HTML report
       if: ${{ always() && inputs.upload_report }}
-      uses: actions/cache/save@6849a6489940f00c2f30c0fb92c6274307ccb58a # v4.1.2
+      uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
       with:
         path: ur-repo/benchmark_results.html
         key: benchmark-results-${{ matrix.adapter.str_name }}-${{ github.run_id }}

.github/workflows/docs.yml

@@ -52,7 +52,7 @@ jobs:
 
       - name: Download benchmark HTML
         id: download-bench-html
-        uses: actions/cache/restore@6849a6489940f00c2f30c0fb92c6274307ccb58a # v4.1.2
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
         with:
           path: ur-repo/benchmark_results.html
           key: benchmark-results-