Update dependency @rollup/plugin-commonjs to v29

Author: renovate[bot]

package.json

@@ -36,7 +36,7 @@
   },
   "homepage": "https://github.com/esm-bundle/markdown-it#readme",
   "devDependencies": {
-    "@rollup/plugin-commonjs": "21.1.0",
+    "@rollup/plugin-commonjs": "29.0.0",
     "@rollup/plugin-json": "6.1.0",
     "@rollup/plugin-node-resolve": "13.3.0",
     "chai": "4.3.4",