automation: Update lemmy Docker tag to v0.18.5

This MR contains the following updates:

Package	Update	Change
lemmy	patch	0.18.4 -> 0.18.5

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Release Notes

LemmyNet/lemmy

v0.18.5: Release

Compare Source

See Releases.md

Full Changelog: https://github.com/LemmyNet/lemmy/compare/0.18.4...0.18.5

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Configuration

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