test: Fix guest_env_test.go

The test used `go:build iso` so it was not included in the integration
tests. Change to `go:build integration` so we test in the CI.

Rename the file and the test name to make it more clear that this test
is about the iso image.

Skip the test for non vm-driver, since this tests is about the iso
image.

We may need to add a similar test or adapt this test so it can be used
also with the kicbase image.

This test will be useful to validate #21800, avoiding regressions such
as #21788.

test/integration/iso_test.go

@@ -1,4 +1,4 @@
-//go:build iso
+//go:build integration
 
 /*
 Copyright 2016 The Kubernetes Authors All rights reserved.
@@ -28,8 +28,12 @@ import (
 	"k8s.io/minikube/pkg/minikube/vmpath"
 )
 
-// TestGuestEnvironment verifies files and packages installed inside minikube ISO/Base image
-func TestGuestEnvironment(t *testing.T) {
+// TestISOImage verifies files and packages installed inside minikube ISO/Base image
+func TestISOImage(t *testing.T) {
+	if !VMDriver() {
+		t.Skip("This test requires a VM driver")
+	}
+
 	MaybeParallel(t)
 
 	profile := UniqueProfileName("guest")