Cache go modules

Author: benashz

.github/workflows/build.yaml

@@ -41,6 +41,8 @@ jobs:
         uses: actions/setup-go@cdcb36043654635271a94b9a6d1392de5bb323a7 # v5.0.1
         with:
           go-version-file: .go-version
+          cache-dependency-path: |
+            go.sum
       - name: go fmt
         run: |
           make check-fmt