Bump hacking

hacking 3.0.x is too old. Bump it to the version currently used in
tempest repo.

Also remove the note about old pip's behavior because recent pip does
not require specific order.

Depends-on: https://review.opendev.org/c/openstack/tempest/+/906634
Change-Id: I9a7760dcbcba15213deaa03e3c2a5f42446905d1
diff --git a/keystone_tempest_plugin/tests/scenario/keycloak.py b/keystone_tempest_plugin/tests/scenario/keycloak.py
index 50c3495..ef2b01d 100644
--- a/keystone_tempest_plugin/tests/scenario/keycloak.py
+++ b/keystone_tempest_plugin/tests/scenario/keycloak.py
@@ -26,7 +26,7 @@
 
     @property
     def url_base(self):
-        return self.keycloak_url + f'/admin/realms'
+        return self.keycloak_url + '/admin/realms'
 
     @property
     def token_endpoint(self):