Bump DavidAnson/markdownlint-cli2-action from 18 to 19 in the actions group (#386)

Author: jorenham

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: markdownlint
-        uses: DavidAnson/markdownlint-cli2-action@v18
+        uses: DavidAnson/markdownlint-cli2-action@v19
         with:
           config: ".markdownlint.yaml"
           globs: "**/*.md"