Bump actions/setup-node from 4 to 6

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 4 to 6.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v4...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/manual-proxy-environment-deploy.yaml

@@ -30,7 +30,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 24
 

.github/workflows/stage-5-publish.yaml

@@ -343,7 +343,7 @@ jobs:
         with:
           path: .
           name: sdk-ts-${{ inputs.version }}
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: '24.3'
           registry-url: 'https://npm.pkg.github.com'