monitors/alsa: Increase headroom for VMware and VirtualBox

Ubuntu received reports of very bad audio stuttering when running
25.10 in VMware & Virtualbox on Windows 11 hosts.

ac0d8ee4a8 dropped the headroom from
8192 samples to 2048. This seems fine for QEMU+KVM, but for unknown
reasons, the system emulation on Windows with these VMware/Virtualbox
is much slower, and xruns become frequent.

See:
https://bugs.launchpad.net/ubuntu/+source/wireplumber/+bug/2127250
https://discourse.ubuntu.com/t/vm-ubuntu2025-10-on-vmware-workstation-and-sound-problem/71066/3

src/config/wireplumber.conf.d/alsa-vm.conf

@@ -19,5 +19,25 @@ monitor.alsa.rules = [
         api.alsa.headroom      = 2048
       }
     }
+  },
+  # VMware & VirtualBox on Windows hosts require more headroom to
+  # avoid stuttering.
+  {
+    matches = [
+      {
+        node.name = "~alsa_input.pci.*"
+        cpu.vm.name = "~^(vmware)|(oracle)$"
+      }
+      {
+        node.name = "~alsa_output.pci.*"
+        cpu.vm.name = "~^(vmware)|(oracle)$"
+      }
+    ]
+    actions = {
+      update-props = {
+        api.alsa.period-size   = 1024
+        api.alsa.headroom      = 8192
+      }
+    }
   }
 ]