Module for toml not in dependencies, fails on old distros

In Ubuntu 22.04 and older, looks like toml is required but is not in the dependencies.

Manifested in https://gitlab.nic.cz/labs/bird/-/pipelines/140417

$ apkg build -a bird-$(cat VERSION)*.tar.gz
I building packages
Requested operation requires TOML load module but none was found.
Please install one of following Python modules:
- tomli
- toml
- tomlkit