debian/control: don't require dh-systemd as it's transitional now

4 jobs for feature/backport-2.12 in 128 minutes and 34 seconds (queued for 10 seconds)
Name Stage Failure
build/raspbian/bullseye Build
make[2]: Leaving directory '/builds/packaging/raspbian-icinga2/build/icinga2/obj-arm-linux-gnueabihf'
dh_auto_build: error: cd obj-arm-linux-gnueabihf && make -j6 VERBOSE=1 returned exit code 2
make[1]: *** [debian/rules:45: override_dh_auto_build] Error 25
make[1]: Leaving directory '/builds/packaging/raspbian-icinga2/build/icinga2'
make: *** [debian/rules:40: build] Error 2
dpkg-buildpackage: error: debian/rules build subprocess returned exit status 2
[ binary build failed! ]
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1