Pin zope.event (#4531)

zope.event [released](https://pypi.org/project/zope.event/#history) a
new version recently that broke our gevent ci

Author: sentrivana

scripts/populate_tox/tox.jinja

@@ -173,6 +173,7 @@ deps =
     {py3.6,py3.7}-gevent: pytest<7.0.0
     {py3.8,py3.9,py3.10,py3.11,py3.12}-gevent: pytest
     gevent: pytest-asyncio
+    {py3.10,py3.11}-gevent: zope.event<5.0.0
 
     # === Integrations ===
 

tox.ini

@@ -336,6 +336,7 @@ deps =
     {py3.6,py3.7}-gevent: pytest<7.0.0
     {py3.8,py3.9,py3.10,py3.11,py3.12}-gevent: pytest
     gevent: pytest-asyncio
+    {py3.10,py3.11}-gevent: zope.event<5.0.0
 
     # === Integrations ===