Use Debian Bookworm and Node 20 LTS for the bot image

[weeman1337]

• We use Node 20 for the CI. So let's use it for the image too
• Update Debian to Bookworm, because it supports s390x

:heavy_check_mark: Checklist

• [x] A changeset describing the change and affected packages (more info).
• [ ] Added or updated documentation.
• [ ] Tests for new functionality and regression tests for bug fixes.
• [ ] Screenshots or videos attached (for UI changes).
• [x] All your commits have a Signed-off-by line in the message (more info).

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: 4dcdc506b219f58b642b9702a39022eecbb1322f

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

| Name | Type | | ---------------------------- | ----- | | @nordeck/matrix-meetings-bot | Patch |

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