Update zope.event from 4.3.0 to 4.4 (#4104)

requirements/dev.txt

@@ -116,8 +116,9 @@ pytest-base-url==1.4.1 \
     --hash=sha256:7425e8163345494ac7f544e99c6f3e5a08f4228bee5e26013b98c462a4d31f6e
 
 # Required by PyPOM
-zope.event==4.3.0 \
-    --hash=sha256:57b5fefd1d92774a7c26d7307b7ad9d0eac2181fd320b2061e69216e2a3b3a07
+zope.event==4.4 \
+    --hash=sha256:d8e97d165fd5a0997b45f5303ae11ea3338becfe68c401dd88ffd2113fe5cae7 \
+    --hash=sha256:69c27debad9bdacd9ce9b735dad382142281ac770c4a432b533d6d65c4614bcf
 zope.interface==4.5.0 \
     --hash=sha256:467d364b24cb398f76ad5e90398d71b9325eb4232be9e8a50d6a3b3c7a1c8789 \
     --hash=sha256:3d184aff0756c44fff7de69eb4cd5b5311b6f452d4de28cb08343b3f21993763 \