Prevent generating outbound traffic on a non-loopback interface during tests.
- Fix
node_init_tests/init_test - Change CI to catch new regressions, including DNS traffic. DNS traffic is detected because some VMs have configured a non-loopback DNS server,
[1111:1111::1]:53. This is achieved by runningtcpdumpduring tests and inspecting its output after the tests. Add--cap-add NET_RAWto docker to be able to runtcpdump.
Resolves #31339