Bump gatsby-plugin-typescript from 2.4.16 to 2.12.1

Bumps [gatsby-plugin-typescript](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-typescript) from 2.4.16 to 2.12.1.
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/gatsby-plugin-typescript@2.12.1/packages/gatsby-plugin-typescript/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-plugin-typescript@2.12.1/packages/gatsby-plugin-typescript)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -28,7 +28,7 @@
     "gatsby-plugin-react-svg": "^3.0.0",
     "gatsby-plugin-remove-serviceworker": "^1.0.0",
     "gatsby-plugin-sharp": "^2.6.24",
-    "gatsby-plugin-typescript": "^2.4.16",
+    "gatsby-plugin-typescript": "^2.12.1",
     "gatsby-source-contentful": "^2.3.34",
     "gatsby-source-filesystem": "^2.3.23",
     "gatsby-transformer-remote-filesystem": "^1.0.0",