Merge branch 'selftests-bpf-enfoce-so_reuseaddr-in-basic-test-servers'

Alexis Lothoré says:

====================
This small series is another follow-up to [1], in which I misunderstood
Martin's initial feedback (see [2]). I proposed to make tc-tunnel apply
SO_REUSEPORT once server is brought up. This series updates
start_server_addr to really apply Martin's proposal after his
clarification [3]

[1] https://lore.kernel.org/bpf/20251031-tc_tunnel_improv-v1-0-0ffe44d27eda@bootlin.com/
[2] https://lore.kernel.org/bpf/efa3540a-1f52-46ca-9f49-e631a5e3e48c@linux.dev/
[3] https://lore.kernel.org/bpf/4cbabdf1-af2c-490a-a41a-b40c1539c1cb@linux.dev/
====================

Link: https://patch.msgid.link/20251105-start-server-soreuseaddr-v1-0-1bbd9c1f8d65@bootlin.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>