Bump shell-quote and @bradgarropy/gatsby-plugin-seo

Bumps [shell-quote](https://github.com/substack/node-shell-quote) to 1.7.3 and updates ancestor dependency [@bradgarropy/gatsby-plugin-seo](https://github.com/bradgarropy/gatsby-plugin-seo). These dependencies need to be updated together.


Updates `shell-quote` from 1.7.2 to 1.7.3
- [Release notes](https://github.com/substack/node-shell-quote/releases)
- [Commits](https://github.com/substack/node-shell-quote/commits)

Updates `@bradgarropy/gatsby-plugin-seo` from 1.1.1 to 2.2.0
- [Release notes](https://github.com/bradgarropy/gatsby-plugin-seo/releases)
- [Commits](bradgarropy/gatsby-plugin-seo@v1.1.1...v2.2.0)

---
updated-dependencies:
- dependency-name: shell-quote
  dependency-type: indirect
- dependency-name: "@bradgarropy/gatsby-plugin-seo"
  dependency-type: direct:production
...

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