Update module github.com/emersion/go-message to v0.18.1

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
github.com/emersion/go-message	v0.17.0 -> v0.18.1

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Release Notes

emersion/go-message (github.com/emersion/go-message)

### [`v0.18.1`](https://redirect.github.com/emersion/go-message/releases/tag/v0.18.1): 0.18.1 [Compare Source](https://redirect.github.com/emersion/go-message/compare/v0.18.0...v0.18.1) ### [`v0.18.0`](https://redirect.github.com/emersion/go-message/releases/tag/v0.18.0): 0.18.0 [Compare Source](https://redirect.github.com/emersion/go-message/compare/v0.17.0...v0.18.0)

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

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

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

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