update actions/cache to v4 (kubesphere#295)

* update actions/cache to v4

Signed-off-by: wanjunlei <wanjunlei@kubesphere.io>

* update actions/cache to v4

Signed-off-by: wanjunlei <wanjunlei@kubesphere.io>

---------

Signed-off-by: wanjunlei <wanjunlei@kubesphere.io>

Author: wanjunlei

.github/workflows/main.yaml

@@ -65,7 +65,7 @@ jobs:
         with:
           go-version: 1.20.x
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v4
         with:
           path: ~/go/pkg/mod
           key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
@@ -88,7 +88,7 @@ jobs:
         with:
           go-version: 1.20.x
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v4
         with:
           path: ~/go/pkg/mod
           key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}