linux: update kernel headers from v6.15-rc7

src/basic/include/linux/bpf.h

@@ -4968,6 +4968,9 @@ union bpf_attr {
  * 		the netns switch takes place from ingress to ingress without
  * 		going through the CPU's backlog queue.
  *
+ * 		*skb*\ **->mark** and *skb*\ **->tstamp** are not cleared during
+ * 		the netns switch.
+ *
  * 		The *flags* argument is reserved and must be 0. The helper is
  * 		currently only supported for tc BPF program types at the
  * 		ingress hook and for veth and netkit target device types. The