Add multiattach skip check to VolumeRetypeMultiattachTest

The new VolumeRetypeMultiattachTest added in change [1] may
break drivers that don't support the multiattach feature.

This patch fixes this issue by adding a skip check for
multiattach to the VolumeRetypeMultiattachTest test class.

[1] https://review.opendev.org/c/openstack/tempest/+/956225

Change-Id: Ie3df5e603addb05a8401f119ac47515a276e69d6
Signed-off-by: Fernando Ferraz <fernandoperches@gmail.com>
diff --git a/tempest/api/volume/admin/test_volume_retype.py b/tempest/api/volume/admin/test_volume_retype.py
index 251cf8e..e19038e 100644
--- a/tempest/api/volume/admin/test_volume_retype.py
+++ b/tempest/api/volume/admin/test_volume_retype.py
@@ -213,6 +213,12 @@
     volume_max_microversion = 'latest'
 
     @classmethod
+    def skip_checks(cls):
+        super(VolumeRetypeMultiattachTest, cls).skip_checks()
+        if not CONF.compute_feature_enabled.volume_multiattach:
+            raise cls.skipException('Volume multi-attach is not available.')
+
+    @classmethod
     def resource_setup(cls):
         super(VolumeRetypeMultiattachTest, cls).resource_setup()
         extra_specs_src = {"multiattach": '<is> True'}