Update dependency gatsby to v2.29.2

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
gatsby (changelog)	2.29.1 -> 2.29.2

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Release Notes

gatsbyjs/gatsby

### [`v2.29.2`](https://togithub.com/gatsbyjs/gatsby/compare/gatsby@2.29.1...gatsby@2.29.2) [Compare Source](https://togithub.com/gatsbyjs/gatsby/compare/gatsby@2.29.1...gatsby@2.29.2)

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Renovate configuration

:date: Schedule: "every weekend" in timezone America/Los_Angeles.

:vertical_traffic_light: Automerge: Enabled.

:recycle: Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

:no_bell: Ignore: Close this PR and you won't be reminded about this update again.

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