add patch to disable graph locking

add patch to disable graph locking

There are still some issues with graph locking, e.g. deadlocks during
backup canceling [0] and initial attempts to fix it didn't work [1].
Because the AioContext locks still exist, it should still be safe to
disable graph locking.

[0]: https://lists.nongnu.org/archive/html/qemu-devel/2023-09/msg00729.html
[1]: https://lists.nongnu.org/archive/html/qemu-devel/2023-09/msg06905.html

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>