Bump gatsby from 5.6.1 to 5.9.1

Bumps [gatsby](https://github.com/gatsbyjs/gatsby) from 5.6.1 to 5.9.1.
- [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@5.6.1...gatsby@5.9.1)

---
updated-dependencies:
- dependency-name: gatsby
  dependency-type: direct:production
...

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

Author: dependabot[bot]

package.json

@@ -19,7 +19,7 @@
     "classnames": "^2.3.1",
     "core-js": "^3.18.3",
     "dateformat": "^5.0.3",
-    "gatsby": "^5.0.0",
+    "gatsby": "^5.9.1",
     "gatsby-plugin-feed": "^5.6.0",
     "gatsby-plugin-image": "^3.0.0",
     "gatsby-plugin-json-output": "^1.2.0",