Maintainership of Usage

[Adrien Plazas <kekun plazas laposte net>]

Hi all,

The Usage application seems to be unmaintained since 9 months at least, 
while Felipe Borges resigned in due form a few months ago, the 
remaining listed maintainer, Petr Štětka, isn't giving any sign of 
life on our GitLab instance since at least a year.

Do you mind if I take maintainership over so we can at the very least 
fix the build and merge the MRs waiting since now 9 months?

Cheers,
Adrien Plazas