build(deps): bump sharp and gatsby-plugin-manifest

Bumps [sharp](https://github.com/lovell/sharp) to 0.30.7 and updates ancestor dependency [gatsby-plugin-manifest](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-manifest). These dependencies need to be updated together.


Updates `sharp` from 0.25.4 to 0.30.7
- [Release notes](https://github.com/lovell/sharp/releases)
- [Changelog](https://github.com/lovell/sharp/blob/main/docs/changelog.md)
- [Commits](https://github.com/lovell/sharp/compare/v0.25.4...v0.30.7)

Updates `gatsby-plugin-manifest` from 2.4.13 to 4.23.1
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-manifest/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-plugin-manifest@4.23.1/packages/gatsby-plugin-manifest)

---
updated-dependencies:
- dependency-name: sharp
  dependency-type: indirect
- dependency-name: gatsby-plugin-manifest
  dependency-type: direct:production
...

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

package.json

@@ -17,7 +17,7 @@
   "dependencies": {
     "dateformat": "^3.0.3",
     "gatsby": "^4.23.1",
-    "gatsby-plugin-manifest": "^2.4.13",
+    "gatsby-plugin-manifest": "^4.23.1",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",
     "snyk": "^1.1012.0"