Update dependency gatsby-plugin-mdx to v2.14.1 [SECURITY]

Author: renovate[bot]

package.json

@@ -23,7 +23,7 @@
     "gatsby-plugin-google-analytics": "3.8.0",
     "gatsby-plugin-image": "1.8.0",
     "gatsby-plugin-manifest": "3.8.0",
-    "gatsby-plugin-mdx": "2.8.0",
+    "gatsby-plugin-mdx": "2.14.1",
     "gatsby-plugin-page-creator": "3.8.0",
     "gatsby-plugin-react-helmet": "4.8.0",
     "gatsby-plugin-robots-txt": "1.6.8",