chore(deps): update ghcr.io/siderolabs/omni docker tag to v0.42.3

[p6r-renovate[bot]]

This PR contains the following updates:

Package	Update	Change
ghcr.io/siderolabs/omni	patch	v0.42.2 -> v0.42.3

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Release Notes

siderolabs/omni (ghcr.io/siderolabs/omni)

### [`v0.42.3`](https://redirect.github.com/siderolabs/omni/compare/v0.42.2...v0.42.3) [Compare Source](https://redirect.github.com/siderolabs/omni/compare/v0.42.2...v0.42.3)

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Configuration

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