Cap Sphinx to 6.0.0 (#2950)

AA-Turner · web-flow · commit 8d3c3fdedc7d · 2023-01-06T16:50:42.000Z
diff --git a/requirements.txt b/requirements.txt
@@ -1,6 +1,6 @@
 # Requirements for building PEPs with Sphinx
 Pygments >= 2.9.0
-Sphinx >= 5.1.1
+Sphinx >= 5.1.1,<=6.0.0
 docutils >= 0.19.0
 
 # For RSS
