⬆️ Bump gatsby-source-filesystem from 3.0.0 to 3.1.0

Bumps [gatsby-source-filesystem](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-source-filesystem) from 3.0.0 to 3.1.0.
- [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/gatsby-source-filesystem@3.1.0/packages/gatsby-source-filesystem)

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

package.json

@@ -21,7 +21,7 @@
     "gatsby-plugin-sharp": "^3.1.0",
     "gatsby-plugin-sitemap": "^3.0.0",
     "gatsby-source-contentful": "^5.1.0",
-    "gatsby-source-filesystem": "^3.0.0",
+    "gatsby-source-filesystem": "^3.1.0",
     "gatsby-transformer-sharp": "^3.0.0",
     "react": "^17.0.1",
     "react-dom": "^17.0.1",