Support Multi-Arch Image in CI (#4348)

* Add KuberayTestArch environment variable for architecture override in tests

This commit introduces a new environment variable KuberayTestArch that allows
overriding the detected architecture in test environments. Previously, the
system only relied on runtime.GOARCH to determine if ARM64 architecture was
being used, but this change enables explicit architecture specification
through the environment variable. This is particularly useful for testing
scenarios where you want to force a specific architecture regardless of the
actual runtime environment, improving test flexibility and consistency
across different platforms.

Signed-off-by: KunWuLuan <kunwuluan@gmail.com>

* update

Signed-off-by: Future-Outlier <eric901201@gmail.com>

---------

Signed-off-by: KunWuLuan <kunwuluan@gmail.com>
Signed-off-by: Future-Outlier <eric901201@gmail.com>
Co-authored-by: Future-Outlier <eric901201@gmail.com>

Author: KunWuLuan

ray-operator/test/support/environment.go

@@ -1,10 +1,7 @@
 package support
 
 import (
-	"fmt"
 	"os"
-	"runtime"
-	"strings"
 )
 
 const (
@@ -25,15 +22,7 @@ func GetRayVersion() string {
 }
 
 func GetRayImage() string {
-	rayImage := lookupEnvOrDefault(KuberayTestRayImage, RayImage)
-	// detect if we are running on arm64 machine, most likely apple silicon
-	// the os name is not checked as it also possible that it might be linux
-	// also check if the image does not have the `-aarch64` suffix
-	if runtime.GOARCH == "arm64" && !strings.HasSuffix(rayImage, "-aarch64") {
-		rayImage = rayImage + "-aarch64"
-		fmt.Printf("Modified Ray Image to: %s for ARM chips\n", rayImage)
-	}
-	return rayImage
+	return lookupEnvOrDefault(KuberayTestRayImage, RayImage)
 }
 
 func GetKubeRayUpgradeVersion() string {