ci(github-actions): 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/github-ci.yml

@@ -20,7 +20,7 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Setup Node.js
-      uses: actions/setup-node@v4
+      uses: actions/setup-node@v6
       with:
         node-version: 20.11.0
 

.github/workflows/release-please.yml

@@ -42,7 +42,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v4
     - name: Node.js LTS
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v6
       with:
         node-version: 24.x
     - name: Publish to npm

.github/workflows/test.yml

@@ -24,7 +24,7 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Setup Node.js
-      uses: actions/setup-node@v4
+      uses: actions/setup-node@v6
       with:
         node-version: ${{ matrix.version }}
 
@@ -52,7 +52,7 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Use Node.js LTS
-      uses: actions/setup-node@v4
+      uses: actions/setup-node@v6
       with:
         node-version: 22.x