[DNM] Testing docs bump with new Sphinx

Sphinx updates can be scary.  This change leverages a constraints bump to see what breaks.

Depends-On: https://review.opendev.org/c/openstack/requirements/+/916565
Change-Id: Id3ac0705eb2b46f68d6bc3ae15dcf72bbcffb6c9

doc/requirements.txt

@@ -6,3 +6,4 @@ doc8>=0.8.1 # Apache-2.0
 # The below is rewquired to build testing module reference
 mock>=2.0.0 # BSD
 pytest>=5.3.5 # MIT
+# Force docs rebuild: 

requirements.txt

@@ -67,3 +67,4 @@ XStatic-tv4>=1.2.7.0 # MIT
 # Most horizon plugins do not have enmerkar in their requirements.txt
 # and they depends on horizon requirements, so we keep it here.
 enmerkar>=0.7.1 # BSD
+# Force requirements rebuild: 

setup.py

@@ -19,3 +19,5 @@ import setuptools
 setuptools.setup(
     setup_requires=['pbr>=2.0.0'],
     pbr=True)
+
+# Force unittests: