Add T2A machine types to validMachineTypes (#232)

Relevant docs https://cloud.google.com/compute/docs/general-purpose-machines#t2a_machines

Author: glindstedt

rules/utils.go

@@ -84,6 +84,13 @@ var validMachineTypes = map[string]bool{
 	"n2d-highcpu-96":   true,
 	"n2d-highcpu-128":  true,
 	"n2d-highcpu-224":  true,
+	"t2a-standard-1":   true,
+	"t2a-standard-2":   true,
+	"t2a-standard-4":   true,
+	"t2a-standard-8":   true,
+	"t2a-standard-16":  true,
+	"t2a-standard-32":  true,
+	"t2a-standard-48":  true,
 	"t2d-standard-1":   true,
 	"t2d-standard-2":   true,
 	"t2d-standard-4":   true,