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

Bumps [got](https://github.com/sindresorhus/got) to 11.8.6 and updates ancestor dependencies [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 need to be updated together.


Updates `got` from 7.1.0 to 11.8.6
- [Release notes](https://github.com/sindresorhus/got/releases)
- [Commits](sindresorhus/got@v7.1.0...v11.8.6)

Updates `gatsby` from 2.32.13 to 5.6.0
- [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/[email protected]@5.6.0)

Updates `gatsby-plugin-sharp` from 2.14.4 to 5.6.0
- [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/[email protected]/packages/gatsby-plugin-sharp)

Updates `gatsby-source-filesystem` from 2.11.1 to 5.6.0
- [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/[email protected]/packages/gatsby-source-filesystem)

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

Signed-off-by: dependabot[bot] <[email protected]>