chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/go.yml

@@ -20,7 +20,7 @@ jobs:
       with:
         go-version: ${{ matrix.go }}
 
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Tidy
       run: |