Upgrade to non-failing, non-deprecated actions/cache

This request has been automatically failed because it uses a deprecated version of `actions/cache: v3.0.2`. Please update your workflow to use v3/v4 of actions/cache to avoid interruptions. Learn more: https://github.blog/changelog/2024-12-05-notice-of-upcoming-releases-and-breaking-changes-for-github-actions/#actions-cache-v1-v2-and-actions-toolkit-cache-package-closing-down

Author: hugovk

.github/workflows/build.yml

@@ -227,7 +227,7 @@ jobs:
         echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> $GITHUB_ENV
     - name: 'Restore OpenSSL build'
       id: cache-openssl
-      uses: actions/cache@v3.0.2
+      uses: actions/cache@v4
       with:
         path: ./multissl/openssl/${{ env.OPENSSL_VER }}
         key: ${{ runner.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
@@ -275,7 +275,7 @@ jobs:
         echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> $GITHUB_ENV
     - name: 'Restore OpenSSL build'
       id: cache-openssl
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ./multissl/openssl/${{ env.OPENSSL_VER }}
         key: ${{ runner.os }}-multissl-openssl-${{ env.OPENSSL_VER }}