Bump gatsby from 3.11.1 to 3.12.0 in /packages/website

Bumps [gatsby](https://github.com/gatsbyjs/gatsby) from 3.11.1 to 3.12.0.
- [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/gatsby@3.11.1...gatsby@3.12.0)

---
updated-dependencies:
- dependency-name: gatsby
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

packages/website/package.json

@@ -15,7 +15,7 @@
     "copy-text-to-clipboard": "^3.0.1",
     "crypto-browserify": "^3.12.0",
     "framer-motion": "^4.1.17",
-    "gatsby": "^3.11.1",
+    "gatsby": "^3.12.0",
     "gatsby-background-image": "^1.5.3",
     "gatsby-image": "^3.11.0",
     "gatsby-plugin-image": "^1.12.0",