chore(deps): bump actions/setup-node from 3 to 6

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 3 to 6.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/v3...v6)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/git-sync-test.yml

@@ -129,7 +129,7 @@ jobs:
         with:
           deno-version: v2.x
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: "20"