feat: increasing cores + threads to leverage higher performance runner

qemu.pkr.hcl

@@ -17,6 +17,8 @@ source "qemu" "qemu-amd64" {
   ssh_wait_timeout  = "5m"
   vnc_port_min      = 5901
   vnc_port_max      = 5901
+  cores             = 8
+  threads           = 16
   qemuargs          = [
     ["-m", "4096M"],
     ["-smp", "2"],
@@ -74,4 +76,4 @@ packer {
         version = "1.1.0"
         }
     }
-}
+}