Bump got, gatsby, gatsby-plugin-sharp and gatsby-source-filesystem

Bumps [got](https://github.com/sindresorhus/got), [gatsby](https://github.com/gatsbyjs/gatsby), [gatsby-plugin-sharp](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-sharp) and [gatsby-source-filesystem](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-source-filesystem). These dependencies needed to be updated together.

Updates `got` from 7.1.0 to 11.8.5
- [Release notes](https://github.com/sindresorhus/got/releases)
- [Commits](sindresorhus/got@v7.1.0...v11.8.5)

Updates `gatsby` from 2.24.15 to 4.21.1
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/compare/gatsby@2.24.15...gatsby@4.21.1)

Updates `gatsby-plugin-sharp` from 2.6.24 to 4.21.0
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-sharp/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-plugin-sharp@4.21.0/packages/gatsby-plugin-sharp)

Updates `gatsby-source-filesystem` from 2.3.23 to 4.21.1
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-source-filesystem/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-source-filesystem@4.21.1/packages/gatsby-source-filesystem)

---
updated-dependencies:
- dependency-name: got
  dependency-type: indirect
- dependency-name: gatsby
  dependency-type: direct:production
- dependency-name: gatsby-plugin-sharp
  dependency-type: direct:production
- dependency-name: gatsby-source-filesystem
  dependency-type: direct:development
...

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

Author: dependabot[bot]