chore(nix): support build for experimental feature

[maiste]

Following the merge of #10724, I have written this PR so we are able to build the executable using Nix Flake. I'm far from being a Nix expert, so if someone with a better expertise is able to reduce the amount of code, it would be happy to change the code :smile:

EDIT: Replace my solution with @gridbugs' one, as it is simpler and more elegant one. It consists in adding a function to the package default that could take some flags.