Merge branch 'net_sched-fix-hfsc-qlen-backlog-accounting-bug-and-add-selftest'

Cong Wang says:

====================
net_sched: Fix HFSC qlen/backlog accounting bug and add selftest

This series addresses a long-standing bug in the HFSC qdisc where queue length
and backlog accounting could become inconsistent if a packet is dropped during
a peek-induced dequeue operation, and adds a corresponding selftest to tc-testing.
====================

Link: https://patch.msgid.link/20250518222038.58538-1-xiyou.wangcong@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>