Bump actions/setup-go from 5 to 6 (#365)

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -81,7 +81,7 @@ jobs:
     runs-on: macos-26
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@v6
         with:
           go-version: 1.23.x
       - name: Run unit tests