Pin sphinx version to less than 7.2 (#10655)

The recent Sphinx 7.2 release is causing errors during docs jobs around
the furo style sheet. There seems to be a compatibility issue between
furo, qiskit_sphinx_theme, and this new Sphinx release. While the issue
is getting resolved this commit pins the sphinx version we use in CI and
for local docs builds to avoid the new release.

requirements-dev.txt

@@ -31,7 +31,7 @@ ddt>=1.2.0,!=1.4.0,!=1.4.3
 # components of Terra use some of its optional dependencies in order to document
 # themselves.  These are the requirements that are _only_ required for the docs
 # build, and are not used by Terra itself.
-Sphinx>=6.0
+Sphinx>=6.0,<7.2
 qiskit-sphinx-theme~=1.14.0
 sphinx-design>=0.2.0
 sphinx-remove-toctrees