selftests/bpf: migrate cgroup sock create test for prohibiting sockets

selftests/bpf: migrate cgroup sock create test for prohibiting sockets

This patch continues the migration and removal process for cgroup
sock_create tests to selftests.

The test being migrated verifies the ability of cgroup BPF to block the
creation of specific types of sockets using a verdict. Specifically, the
test denies socket creation when the socket is of type AF_INET{6},
SOCK_DGRAM, and IPPROTO_ICMP{V6}. If the requested socket type matches
these attributes, the cgroup BPF verdict blocks the socket creation.

As with the previous commit, this test currently lacks coverage in
selftests, so this patch migrates the functionality into the sock_create
tests under selftests. This migration ensures that the socket creation
blocking behavior with cgroup bpf program is properly tested within the
selftest framework.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20241011044847.51584-3-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>