Merge pull request #168 from andthum/dependabot/pip/docs/sphinx-gte-5.0-and-lt-9.0

Update sphinx requirement from <8.0,>=5.0 to >=5.0,<9.0 in /docs

Author: andthum

docs/requirements-docs.txt

@@ -1,5 +1,5 @@
 # Requirements to build hpcss' documentation.
 
-sphinx >=5.0, <8.0
+sphinx >=5.0, <9.0
 sphinx-rtd-theme >=1.0, <3.0
 tomlkit >=0.1, < 1.0