Remove panko_available

... because Panko was retired during Xena cycle and the parameter was
deprecated then[1].

[1] d273aa3c56

Change-Id: I0fd7481e09dbf897dab4a8d726a7d852d0e77a09

manifests/init.pp

@@ -229,8 +229,6 @@
 #   Defaults to $::os_service_default
 #
 # DEPREACTED PARAMETERS
-#  [*panko_available*]
-#   Defaults to undef
 #  [*keystone_v2*]
 #   Defaults to undef
 #  [*change_password_available*]
@@ -383,7 +381,6 @@ class tempest(
   $load_balancer_global_observer_role = $::os_service_default,
   $load_balancer_test_with_noop       = $::os_service_default,
   # DEPRECATED PARAMETERS
-  $panko_available                    = undef,
   $keystone_v2                        = undef,
   $change_password_available          = undef,
   $glance_v1                          = undef,
@@ -397,10 +394,6 @@ class tempest(
     $tempest_roles_real = $::os_service_default
   }
 
-  if $panko_available != undef {
-    warning('The panko_available parameter has been deprecated and has no effect')
-  }
-
   if $keystone_v2 != undef {
     warning('The keystone_v2 parameter has been deprecated and will be removed in a future release.')
   }

releasenotes/notes/retire-panko-cleanup-7641cca0641e688a.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    The ``tempest::panko_available`` parameter has been removed.