- Cleanup up _service:
+ tar and compress services should be 'buildtime' in combination
with obs_scm.
+ Remove the .tar.xz tarball, only eep the .obscpio archive as
source.
+ Drop stale cage-0.1.5+0.83ffc57.obscpio archive, add
cage-0.1.5+36.e7d8780.obscpio instead: This is the same version
as previously packages as tar.xz.

- BuildRequire pkgconfig(wlroots) instead of wlroots-devel: ensure
we get a devel package that has the correct .pc file (latest
wlroots has the pc file renamed to wlroots-0.18.pc, not matching
the name anymore).