Turns out we need to pin quite a few more plugins. What exactly changed

now (many of these plugins have required 5.0 for years) remains unclear.

Author: hategan

requirements-docs.txt

@@ -11,7 +11,15 @@ Sphinx==4.5.0
 sphinx_rtd_theme
 sphinx-tabs==3.2.0
 sphinx-multiversion
+
+# These are not requirements for PSI/J, but we must pin the version
+# since Sphinx 4.5.0 does not properly do so and later versions of
+# these plugins require Sphinx >= 5.0.0
 sphinxcontrib-applehelp==1.0.4
+sphinxcontrib-devhelp==1.0.2
+sphinxcontrib-htmlhelp==2.0.1
+sphinxcontrib-serializinghtml==1.1.5
+sphinxcontrib-qthelp==1.0.3
 
 # For the web version of the docs
 cloud_sptheme == 1.10.1.post20200504175005