Bump gatsby from 3.4.2 to 3.5.1 in /packages/website

Bumps [gatsby](https://github.com/gatsbyjs/gatsby) from 3.4.2 to 3.5.1.
- [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@3.4.2...gatsby@3.5.1)

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": "^4.1.15",
-    "gatsby": "^3.4.2",
+    "gatsby": "^3.5.1",
     "gatsby-background-image": "^1.5.3",
     "gatsby-image": "^3.4.0",
     "gatsby-plugin-image": "^1.4.1",