sched-ext: Disabling debug prevents the build

[extSunset]

Disabling debug prevents the BTF section from being added to vmlinux, whereas libbpf requires it.

Error: failed to load BTF from .../src/linux-6.6/vmlinux: No data available
make[1]: *** [Makefile:208: .../src/linux-6.6/tools/sched_ext/build/obj/bpftool/vmlinux.h] Error 195
make[1]: *** Deleting file '.../src/linux-6.6/tools/sched_ext/build/obj/bpftool/vmlinux.h'
make[1]: Leaving directory '.../src/linux-6.6/tools/bpf/bpftool'
make: *** [Makefile:149: .../src/linux-6.6/tools/sched_ext/build/sbin/bpftool] Error 2

[sirlucjan]

Disabling debug is only optional, I will soon add a flag to prevent the use of this together with sched-ext.