update ZFS submodule to latest git

no actual source code changes, just packaging stuff for bookworm

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/submodules/zfsonlinux b/submodules/zfsonlinux
index b0c4d8ac0b3c0d7de51130b2fd1f3a63efda832c..d855afe7be276f7be4561e55034575055e4ea2e2 160000 (submodule)
--- a/submodules/zfsonlinux
+++ b/submodules/zfsonlinux
@@ -1 +1 @@
-Subproject commit b0c4d8ac0b3c0d7de51130b2fd1f3a63efda832c
+Subproject commit d855afe7be276f7be4561e55034575055e4ea2e2