Bump the gatsby group with 6 updates

Bumps the gatsby group with 6 updates:

| Package | From | To |
| --- | --- | --- |
| [gatsby](https://github.com/gatsbyjs/gatsby) | `5.12.12` | `5.13.0` |
| [gatsby-plugin-image](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-image) | `3.12.3` | `3.13.0` |
| [gatsby-plugin-sharp](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-sharp) | `5.12.3` | `5.13.0` |
| [gatsby-plugin-sitemap](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-sitemap) | `6.12.3` | `6.13.0` |
| [gatsby-source-filesystem](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-source-filesystem) | `5.12.1` | `5.13.0` |
| [gatsby-transformer-sharp](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-transformer-sharp) | `5.12.3` | `5.13.0` |


Updates `gatsby` from 5.12.12 to 5.13.0
- [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]@5.13.0)

Updates `gatsby-plugin-image` from 3.12.3 to 3.13.0
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-image/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/[email protected]/packages/gatsby-plugin-image)

Updates `gatsby-plugin-sharp` from 5.12.3 to 5.13.0
- [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-plugin-sitemap` from 6.12.3 to 6.13.0
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-sitemap/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/[email protected]/packages/gatsby-plugin-sitemap)

Updates `gatsby-source-filesystem` from 5.12.1 to 5.13.0
- [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)

Updates `gatsby-transformer-sharp` from 5.12.3 to 5.13.0
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-transformer-sharp/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/[email protected]/packages/gatsby-transformer-sharp)

---
updated-dependencies:
- dependency-name: gatsby
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gatsby
- dependency-name: gatsby-plugin-image
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gatsby
- dependency-name: gatsby-plugin-sharp
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gatsby
- dependency-name: gatsby-plugin-sitemap
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gatsby
- dependency-name: gatsby-source-filesystem
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gatsby
- dependency-name: gatsby-transformer-sharp
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gatsby
...

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