chore(deps): update actions/setup-go action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -146,7 +146,7 @@ jobs:
           cache: 'npm'
 
       - name: Setup Go (for Go tools testing)
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
           go-version: '1.25'