cherry-pick a few patches from zfs-2.1.7-staging

While checking the current state of 2.1.6 we noticed that there were
some changes in debian-upstream [0] resulting from a bug-report in
zfs-upstream [1].

Our packages should be unaffected (they do not ship the
init-scripts in the first place).
Since the issue was fixed by zfs-upstream already on the
zfs-2.1.7-staging branch we should include it as well as it might save
users, who somehow got debian-upstream's zfs-packages installed on PVE
some trouble.

The other 2 changes seem small and isolated enough so including them
as well.

[0] https://salsa.debian.org/zfsonlinux-team/zfs/-/commits/master
[1] https://github.com/openzfs/zfs/issues/14010

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>

debian/patches/series

@@ -9,3 +9,6 @@
 0009-Patch-move-manpage-arcstat-1-to-arcstat-8.patch
 0010-arcstat-Fix-integer-division-with-python3.patch
 0011-arc-stat-summary-guard-access-to-l2arc-MFU-MRU-stats.patch
+0012-initramfs-use-mount.zfs-instead-of-mount.patch
+0013-etc-mask-zfs-load-key.service.patch
+0014-kcfpool_alloc-should-have-its-argument-list-marked-v.patch