update cache action to v4

.github/workflows/coverity.yml

@@ -25,7 +25,7 @@ jobs:
 
     - name: Cache Coverity
       id: cache-coverity
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ./download/
         key: ${{ runner.os }}-download-${{ hashFiles('**/coverity_tool.*') }}

.github/workflows/unittest-macos.yml

@@ -32,7 +32,7 @@ jobs:
       run: mkdir build
 
     - name: Set up ccache
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ${{ env.CCACHE_DIR }}
         key: macos-ccache-${{ github.sha }}