Merge branch 'selftests-net-isolate-l2_tos_ttl_inherit-sh-in-its-own-netns'

Guillaume Nault says:

====================
selftests/net: Isolate l2_tos_ttl_inherit.sh in its own netns.

l2_tos_ttl_inherit.sh uses a veth pair to run its tests, but only one
of the veth interfaces runs in a dedicated netns. The other one remains
in the initial namespace where the existing network configuration can
interfere with the setup used for the tests.

Isolate both veth devices in their own netns and ensure everything gets
cleaned up when the script exits.

Link: https://lore.kernel.org/netdev/924f1062-ab59-9b88-3b43-c44e73a30387@alu.unizg.hr/
====================

Link: https://lore.kernel.org/r/cover.1673191942.git.gnault@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>