Merge branch 'vsock-test-improve-transport_uaf-test'

Michal Luczaj says:

====================
vsock/test: Improve transport_uaf test

Increase the coverage of a test implemented in commit 301a62dfb0d0
("vsock/test: Add test for UAF due to socket unbinding"). Take this
opportunity to factor out some utility code, drop a redundant sync between
client and server, and introduce a /proc/kallsyms harvesting logic for
auto-detecting registered vsock transports.

v2: https://lore.kernel.org/20250528-vsock-test-inc-cov-v2-0-8f655b40d57c@rbox.co
v1: https://lore.kernel.org/20250523-vsock-test-inc-cov-v1-1-fa3507941bbd@rbox.co
====================

Link: https://patch.msgid.link/20250611-vsock-test-inc-cov-v3-0-5834060d9c20@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>