Dependency updates pending Debian 13 Trixie

[Locke]

Tycho plugins >=4.0.0 require a more recent maven version than Debian 12 Bookworm has.
Dependabot is therefore ignoring this dependency since 5fa200a.

Once Debian 13 Trixie is released and more widely adopted, we need to re-visit that exclusion.

[Locke]

Debian 13 Trixie has been released in August 2025, 13.3 to be released this weekend.

I think we can raise the maven version requirement to upgrade to Tycho plugins >=4.0.0

Note: Debian 12 Bookworm defaults to OpenJDK 17, and Debian 13 Trixie to OpenJDK 21. Consider this and the impact to #155.

Note 2: Debian 12 Bookworm will end being oldstable on June 11, 2026 and become LTS.