.github: bump cache version (#12)

Update the cache action's version.

Author: GiedriusS

.github/workflows/go.yaml

@@ -51,10 +51,14 @@ jobs:
         with:
           go-version: ${{ matrix.go }}
 
-      - uses: actions/cache@v1
+      - uses: actions/cache@v4
         with:
-          path: ~/go/pkg/mod
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
           key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
 
       - name: Run unit tests.
         env: