rules: Add Aurora Graviton2-based T4g and X2g instances (#187)

Author: wata727

rules/aws_db_instance_invalid_type.go

@@ -131,6 +131,13 @@ func NewAwsDBInstanceInvalidTypeRule() *AwsDBInstanceInvalidTypeRule {
 			"db.r6g.2xlarge":            true,
 			"db.r6g.xlarge":             true,
 			"db.r6g.large":              true,
+			"db.x2g.16xlarge":           true,
+			"db.x2g.12xlarge":           true,
+			"db.x2g.8xlarge":            true,
+			"db.x2g.4xlarge":            true,
+			"db.x2g.2xlarge":            true,
+			"db.x2g.xlarge":             true,
+			"db.x2g.large":              true,
 			"db.rv11.24xlarge":          true,
 			"db.rv11.12xlarge":          true,
 			"db.rv11.4xlarge":           true,
@@ -150,6 +157,12 @@ func NewAwsDBInstanceInvalidTypeRule() *AwsDBInstanceInvalidTypeRule {
 			"db.t3.medium":              true,
 			"db.t3.small":               true,
 			"db.t3.micro":               true,
+			"db.t4g.2xlarge":            true,
+			"db.t4g.xlarge":             true,
+			"db.t4g.large":              true,
+			"db.t4g.medium":             true,
+			"db.t4g.small":              true,
+			"db.t4g.micro":              true,
 			"db.x1.32xlarge":            true,
 			"db.x1.16xlarge":            true,
 			"db.x1e.32xlarge":           true,