udpate and rebase to QEMU v6.0.0

Mostly minor changes, bigger ones summarized:
* QEMU's internal backup code now uses a new async system, which allows
  parallel requests - the default max_workers settings is 64, I chose
  less, since 64 put enough stress on QEMU that the guest became
  practically unusable during the backup, and 16 still shows quite a
  nice measureable performance improvement. Little code changes for us
  though.
* 'malformed' QAPI parameters/functions are now a build error (i.e.
  using '_' vs '-'), I chose to just whitelist our calls in the name of
  backwards compatibility.
* monitor OOB race fix now uses the upstream variant, cherry-picked from
  origin/master since it's not in 6.0 by default
* last patch fixes a bug with snapshot rollback related to the new yank
  system

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>

debian/patches/pve/0004-PVE-Config-ui-spice-default-to-pve-certificates.patch

@@ -9,10 +9,10 @@ Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  1 file changed, 9 insertions(+), 6 deletions(-)
 
 diff --git a/ui/spice-core.c b/ui/spice-core.c
-index eea52f5389..d09ee7f09e 100644
+index 272d19b0c1..9719214f19 100644
 --- a/ui/spice-core.c
 +++ b/ui/spice-core.c
-@@ -667,32 +667,35 @@ static void qemu_spice_init(void)
+@@ -694,32 +694,35 @@ static void qemu_spice_init(void)
  
      if (tls_port) {
          x509_dir = qemu_opt_get(opts, "x509-dir");