Remove outdated dependencies

Author: lornajane

package.json

@@ -29,8 +29,6 @@
   "devDependencies": {
     "@hyperjump/json-schema": "^1.11.0",
     "c8": "^10.1.3",
-    "markdownlint-cli": "^0.44.0",
-    "mdv": "^1.3.4",
     "vitest": "^3.0.9",
     "yaml": "^2.7.0"
   },