chore(deps): update dependency gatsby to v3.6.1

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
gatsby (changelog)	3.6.0 -> 3.6.1

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Release Notes

gatsbyjs/gatsby

### [`v3.6.1`](https://togithub.com/gatsbyjs/gatsby/compare/3d607f1ae0cdde12fb8de53e6d0784f83875df25...e9cbed772166a75806e2b014c4f509e51723ebcf) [Compare Source](https://togithub.com/gatsbyjs/gatsby/compare/gatsby@3.6.0...gatsby@3.6.1)

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Configuration

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