Update actions/checkout to v4 in Go workflow

Bump the actions/checkout version from v3 to v4 for the integration tests step in the GitHub Actions Go workflow.

Author: 12ya

.github/workflows/go.yml

@@ -68,7 +68,7 @@ jobs:
         run: go build -o turso cmd/turso/main.go
 
       - name: Integration tests checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: tursodatabase/tursotest
           ref: "main"