Bump DavidAnson/markdownlint-cli2-action in the actions group

Bumps the actions group with 1 update: [DavidAnson/markdownlint-cli2-action](https://github.com/davidanson/markdownlint-cli2-action).


Updates `DavidAnson/markdownlint-cli2-action` from 18 to 19
- [Release notes](https://github.com/davidanson/markdownlint-cli2-action/releases)
- [Commits](DavidAnson/markdownlint-cli2-action@v18...v19)

---
updated-dependencies:
- dependency-name: DavidAnson/markdownlint-cli2-action
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
...

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

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
           plugins: sp-repo-review
 
       - name: markdownlint
-        uses: DavidAnson/markdownlint-cli2-action@v18
+        uses: DavidAnson/markdownlint-cli2-action@v19
         with:
           config: ".markdownlint.yaml"
           globs: "*.md"