Add cache step.

.github/workflows/go.yml

@@ -13,15 +13,28 @@ jobs:
     strategy:
       matrix:
         go:
-        - '1.22'
+        - 'stable'
+        - 'oldstable'
+        - 'current'
     steps:
-    - uses: actions/checkout@v4
+    - name: Checkout the repo
+      uses: actions/checkout@v4
 
     - name: Set up Go
+      if: ${{ matrix.go }} != 'current'
       uses: actions/setup-go@v5
       with:
         go-version: '${{ matrix.go }}'
         check-latest: true
+        cache-dependency-path: ./go.sum
+
+    - name: Set up Go
+      if: ${{ matrix.go }} != 'current'
+      uses: actions/setup-go@v5
+      with:
+        go-version-file: ./go.mod
+        check-latest: true
+        cache-dependency-path: ./go.sum
 
     - name: Build
       run: go build -v ./...