bpftool: Stop supporting BPF offload-enabled feature probing

libbpf 1.0 is not going to support passing ifindex to BPF
prog/map/helper feature probing APIs. Remove the support for BPF offload
feature probing.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220202225916.3313522-3-andrii@kernel.org