ci: bump actions/setup-go from 5 to 6 (#70)

Bumps [actions/setup-go](https://github.com/actions/setup-go) from 5 to 6.
- [Release notes](https://github.com/actions/setup-go/releases)
- [Commits](actions/setup-go@v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-go
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ronald Li 🛠️ <137369375+RonCodes88@users.noreply.github.com>
Co-authored-by: Oliver (Chia-Hong) Chou <49494541+knhn1004@users.noreply.github.com>

Author: 3 people

.github/workflows/ci.yml

@@ -109,7 +109,7 @@ jobs:
     if: needs.changes.outputs.control_plane == 'true'
     steps:
       - uses: actions/checkout@v6
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@v6
         with:
           go-version-file: control-plane/go.mod
       - uses: dtolnay/rust-toolchain@stable