chore(deps): update actions/cache action to v4 (#9)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/unittest.yaml

@@ -31,14 +31,14 @@ jobs:
 
       # Cache go build cache, used to speedup go test
       - name: Go Build Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.go-cache-paths.outputs.go-build }}
           key: ${{ runner.os }}-go-build-${{ hashFiles('**/go.sum') }}
 
       # Cache go mod cache, used to speedup builds
       - name: Go Mod Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.go-cache-paths.outputs.go-mod }}
           key: ${{ runner.os }}-go-mod-${{ hashFiles('**/go.sum') }}
@@ -114,14 +114,14 @@ jobs:
 
       # Cache go build cache, used to speedup go test
       - name: Go Build Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.go-cache-paths.outputs.go-build }}
           key: ${{ runner.os }}-go-build-${{ hashFiles('**/go.sum') }}
 
       # Cache go mod cache, used to speedup builds
       - name: Go Mod Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.go-cache-paths.outputs.go-mod }}
           key: ${{ runner.os }}-go-mod-${{ hashFiles('**/go.sum') }}