Bump actions/setup-node from 5.0.0 to 6.0.0 in the dotnet group

Bumps the dotnet group with 1 update: [actions/setup-node](https://github.com/actions/setup-node).


Updates `actions/setup-node` from 5.0.0 to 6.0.0
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@a0853c2...2028fbc)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: dotnet
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/markdownlint.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
     - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 #@v2
     - name: Use Node.js
-      uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 #@v1
+      uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 #@v1
       with:
         node-version: 12.x
     - name: Run Markdownlint