Skip test_attach_scsi_disk_with_config_drive when barbican integration enabled

Skip because test creates image which should be signed.

Related-Prod: PRODX-25569
Change-Id: I3305e5036c69b1f7f0df35f6b89286ff8565699d
(cherry picked from commit 4cc2eacd7c7e19acc8d55926bed12a36f3c6b018)
diff --git a/tempest/api/compute/admin/test_volume.py b/tempest/api/compute/admin/test_volume.py
index dc631e5..b0f20f6 100644
--- a/tempest/api/compute/admin/test_volume.py
+++ b/tempest/api/compute/admin/test_volume.py
@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import testtools
+
 from tempest.api.compute import base
 from tempest.common import waiters
 from tempest import config
@@ -41,6 +43,9 @@
 class AttachSCSIVolumeTestJSON(BaseAttachSCSIVolumeTest):
     """Test attaching scsi volume to server"""
 
+    @testtools.skipIf(
+        CONF.compute_feature_enabled.barbican_integration_enabled,
+        "Not supported when barbican integration enabled.")
     @decorators.idempotent_id('777e468f-17ca-4da4-b93d-b7dbf56c0494')
     def test_attach_scsi_disk_with_config_drive(self):
         """Test the attach/detach volume with config drive/scsi disk