WastedJobe

Audio Engineer here. Not sure Ardour can open video, but it’s a capable DAW and open source. Reaper is closed source but it can open (and even render) pretty much any video format. To actually seperate a single voice, you do need additional plugins though, no matter which DAW you’re using.
I think iZotope RX could do it, but it is fairly expensive. I haven’t seen any open source audio tools that can do this at all. It is pretty much guaranteed to require some kind of machine learning, as parametrically seperating by EQ or phase won’t work if you have only one source signal (even with two or more microphones, it would be really, really hard).
A very good spectral editor might technically work, it would however take several days of manually deleting select frequencies on an almost single sample level and still sound bad, especially if the noise is nearly the same level as the signal.

They were, no new releases yet though except calendar

It takes work off both the distro maintainers and the developers of the software, because they only need to provide a single package that works anywhere instead of packages for every single distro.