Merge pull request #1 from DLR-KI/dependabot/github_actions/DavidAnson/markdownlint-cli2-action-21

Bump DavidAnson/markdownlint-cli2-action from 20 to 21

Author: HeinrichAD

.github/workflows/main.yml

@@ -85,7 +85,7 @@ jobs:
     needs: [build]
     steps:
       - uses: actions/checkout@v5
-      - uses: DavidAnson/markdownlint-cli2-action@v20
+      - uses: DavidAnson/markdownlint-cli2-action@v21
         with:
           globs: |
             README.md