Add open id dependency (apache#13714)

* Adds python3-openid requirement

Seems that python3-openid dependency is not properly solved by tools
like poetry (it is properly resolved by pip). The result is
that old version of python3-openid is installed when poetry is
used and errors when initdb is run.

While we do not use poetry as an official installation mechanism
this happens frequently enought and it is easy enough to fix
that we can add this dependency to make it easier for
poetry users.

Related to apache#13711 apache#13558 apache#13149

* Update setup.cfg

setup.cfg

@@ -122,6 +122,11 @@ install_requires =
     python-dateutil>=2.3, <3
     python-nvd3~=0.15.0
     python-slugify>=3.0.0,<5.0
+    # Required for flask-openID which comes with flask-appbuilder in case of poetry installation
+    # earlier versions of the dependency are installed but they do not work for Python 3
+    # (pip installs the right version). 
+    # More info: https://github.com/apache/airflow/issues/13149#issuecomment-748705193
+    python3-openid~=3.2
     requests>=2.20.0
     rich==9.2.0
     setproctitle>=1.1.8, <2