Bump DavidAnson/markdownlint-cli2-action from 14 to 15

Bumps [DavidAnson/markdownlint-cli2-action](https://github.com/davidanson/markdownlint-cli2-action) from 14 to 15.
- [Release notes](https://github.com/davidanson/markdownlint-cli2-action/releases)
- [Commits](DavidAnson/markdownlint-cli2-action@v14...v15)

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

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

.github/workflows/verify.yml

@@ -22,7 +22,7 @@ jobs:
           pip install yamllint
           yamllint .
       - uses: bewuethr/shellcheck-action@v2
-      - uses: DavidAnson/markdownlint-cli2-action@v14
+      - uses: DavidAnson/markdownlint-cli2-action@v15
       - name: Run Taplo
         run: |
           curl --fail --silent --show-error --location --output taplo.gz \