Investigate flakiness in TestBuildVMConfiguration/Container_Count_affects_StubDriveCount

[ginglis13]

see these builds from #576 in which TestBuildVMConfiguration/Container_Count_affects_StubDriveCount failed with each failure having the same diff:

• https://github.com/firecracker-microvm/firecracker-containerd/runs/5381251050?check_suite_focus=true
• https://github.com/firecracker-microvm/firecracker-containerd/runs/5379674705?check_suite_focus=true

Diff:
            	            	--- Expected
            	            	+++ Actual
            	            	@@ -52,3 +52,3 @@
            	            	  MachineCfg: (models.MachineConfiguration) {
            	            	-  CPUTemplate: (models.CPUTemplate) (len=2) "C3",
            	            	+  CPUTemplate: (models.CPUTemplate) "",
            	            	   MemSizeMib: (*int64)(128),

Rerunning build succeeded.

[kzys]

It may be due to

firecracker-containerd/internal/cpu_template.go

Line 32 in 004b92f

func SupportCPUTemplate() (bool, error) {

?

https://github.com/actions/virtual-environments doesn't talk much about the underlying CPU vendor (Intel or AMD).