zeroinstall-injector: update to 2.15.

[mobinmob]

0install is now written in ocaml, update and adopt.
Tested on x86_64.

[mobinmob]

And yes, it fails on every builder :P

[mobinmob]

Closing : #19563

[Piraty]

I didn't recognize your PR.
Since you already did work to update to latest release, would you please rebase and incorporate the renaming scheme (if you find it suitable).

Do you actually use zeroinstall?

[mobinmob]

It will not build on ci, but builds and works locally on x86_64. Ι am pretty sure that has to do with the way opam works. Locally it also "contaminates" dirs outside the builddir which creates problems with ./xbps-src clean. The template needs some python deps, but otherwise it is solid.
Yes, I use it ;) . It is not as well-known as flatpak or appimage but does what I need.

[Piraty]

If you could fix contamination, that'd be great!

[mobinmob]

Superseded by: #21039