maint(linux): add more tests for binary package

[https://wiki.debian.org/PhilWyett/DebianMentoring](https://web.archive.org/web/20250324065150/https://wiki.debian.org/PhilWyett/DebianMentoring) lists some tests that are typically run when accepting a package into the Debian repo. We should add some of these tests.

Tests that might be beneficial:

- `lrc` (licenserecon) - Checks that the licenses specified in `copyright` matches reality
- `ratt` (rebuild all the things) - verifies that we don't break package builds of packages that depend on Keyman. Currently this affects fcitx5.
- `reprotest` - verifies that the builds are reproducible

Follows: #13777