Draft: Remove the explicit build and build-indep targets
Mixing these explicit targets with overrides was problematic, e.g. there was no guarantee that the build-source-stamp target would be processed after the quilt and autoreconf dh sequences, that worked only by chance.
To avoid doing the main and udeb builds twice in a full (binary-arch + binary-indep) build, I have decided to do what is different for them in dh_autoreconf overrides. Since dh_autoreconf does only run once, this avoids extra work.
Backported patch from, https://salsa.debian.org/xorg-team/xserver/xorg-server/-/commit/c119638422dbb051d6f575e12df353b2cc3a0f44
This fixes debian bug https://bugs.debian.org/941128