The centos-fedora, opensuse and postmarketos image configurations all
install bpftool but the Debian/Ubuntu ones never did. Only their build
image gets it via the packaging's Build-Depends. So the
TEST-90-RESTRICT-FSACCESS guard and overlay subtests, both gated on
'command -v bpftool', just silently skip there.
Mirror what the build image does. Plain bpftool everywhere except Ubuntu
jammy and noble which still bundle it in linux-tools-generic.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>