Remove deprecated allow_tenant_isolation option

allow_tenant_isolation option of auth and compute groups has been
deprecated over 3 years since I78a4884e980ef7d0103639cb3792a54c69fb7761.
So we have spended much enough time for removing them, this patch does.

Change-Id: I0b0a5e16a5e3785579f95f75fa149b311d918e8c

releasenotes/notes/remove-allow_tenant_isolation-option-03f0d998eb498d44.yaml

@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Remove deprecated config option ``allow_tenant_isolation`` from
+    ``auth`` and ``compute`` groups. Use ``use_dynamic_credentials`` directly
+    instead of the removed option.

tempest/api/identity/v2/test_users.py

@@ -84,7 +84,7 @@ class IdentityUsersTest(base.BaseIdentityV2Test):
         new_pass = data_utils.rand_password()
         user_id = self.creds.user_id
 
-        # to change password back. important for allow_tenant_isolation = false
+        # to change password back. important for use_dynamic_credentials=false
         self.addCleanup(self._restore_password, user_id, old_pass, new_pass)
 
         # user updates own password

tempest/api/identity/v3/test_users.py

@@ -82,7 +82,7 @@ class IdentityV3UsersTest(base.BaseIdentityV3Test):
         old_token = self.non_admin_client.token
         new_pass = data_utils.rand_password()
 
-        # to change password back. important for allow_tenant_isolation = false
+        # to change password back. important for use_dynamic_credentials=false
         self.addCleanup(self._restore_password, old_pass, new_pass)
 
         # user updates own password

tempest/config.py

@@ -61,11 +61,7 @@ AuthGroup = [
                      "users. This option requires that OpenStack Identity "
                      "API admin credentials are known. If false, isolated "
                      "test cases and parallel execution, can still be "
-                     "achieved configuring a list of test accounts",
-                deprecated_opts=[cfg.DeprecatedOpt('allow_tenant_isolation',
-                                                   group='auth'),
-                                 cfg.DeprecatedOpt('allow_tenant_isolation',
-                                                   group='compute')]),
+                     "achieved configuring a list of test accounts"),
     cfg.ListOpt('tempest_roles',
                 help="Roles to assign to all users created by tempest",
                 default=[]),