distro/rhel9: fix ami being hybrid for 9.2 and older

    RHEL 9.2 and older doesn't support UEFI in AWS. The code correctly set
    it for EC2 images, but not for ami. This commit fixes that.

pkg/distro/rhel/rhel9/distro.go

@@ -202,6 +202,15 @@ func newDistro(name string, major, minor int) *rhel.Distribution {
 			ImageFormat: platform.FORMAT_RAW,
 		},
 	}
+
+	// Keep the RHEL EC2 x86_64 images before 9.3 BIOS-only for backward compatibility.
+	// RHEL-internal EC2 images and RHEL AMI images are kept intentionally in sync
+	// with regard to not supporting hybrid boot mode before RHEL version X.Y.
+	// The partitioning table for these reflects that and is also intentionally in sync.
+	if rd.IsRHEL() && common.VersionLessThan(rd.OsVersion(), "9.3") {
+		ec2X86Platform.UEFIVendor = ""
+	}
+
 	x86_64.AddImageTypes(
 		ec2X86Platform,
 		mkAMIImgTypeX86_64(),
@@ -337,16 +346,6 @@ func newDistro(name string, major, minor int) *rhel.Distribution {
 
 		x86_64.AddImageTypes(azureX64Platform, mkAzureSapInternalImgType(rd))
 
-		// keep the RHEL EC2 x86_64 images before 9.3 BIOS-only for backward compatibility
-		if common.VersionLessThan(rd.OsVersion(), "9.3") {
-			ec2X86Platform = &platform.X86{
-				BIOS: true,
-				BasePlatform: platform.BasePlatform{
-					ImageFormat: platform.FORMAT_RAW,
-				},
-			}
-		}
-
 		// add ec2 image types to RHEL distro only
 		x86_64.AddImageTypes(ec2X86Platform, mkEc2ImgTypeX86_64(), mkEc2HaImgTypeX86_64(), mkEC2SapImgTypeX86_64(rd.OsVersion()))