selftests/bpf: Remove with_addr.sh and with_tunnels.sh

Those two scripts were used by test_flow_dissector.sh to setup/cleanup
the network topology before/after the tests. test_flow_dissector.sh
have been deleted by commit 63b37657 ("selftests/bpf: remove
test_flow_dissector.sh") so they aren't used anywhere now.

Remove the two unused scripts and their Makefile entries.

Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250204-with-v1-1-387a42118cd4@bootlin.com