Bump actions/setup-node from 4 to 6 (#44)

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 4 to 6.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/pr-validation.yml

@@ -14,7 +14,7 @@ jobs:
             - uses: actions/checkout@v4
 
             - name: Setup Node.js
-              uses: actions/setup-node@v4
+              uses: actions/setup-node@v6
               with:
                   node-version: '20'
                   cache: 'npm'
@@ -35,7 +35,7 @@ jobs:
             - uses: actions/checkout@v4
 
             - name: Setup Node.js
-              uses: actions/setup-node@v4
+              uses: actions/setup-node@v6
               with:
                   node-version: '20'
                   cache: 'npm'
@@ -53,7 +53,7 @@ jobs:
             - uses: actions/checkout@v4
 
             - name: Setup Node.js
-              uses: actions/setup-node@v4
+              uses: actions/setup-node@v6
               with:
                   node-version: '20'
                   cache: 'npm'
@@ -79,7 +79,7 @@ jobs:
             - uses: actions/checkout@v4
 
             - name: Setup Node.js
-              uses: actions/setup-node@v4
+              uses: actions/setup-node@v6
               with:
                   node-version: '20'
                   cache: 'npm'