Infra: bump Sphinx to 9.0+, limit docutils to <0.22 (#4926)

Author: Secrus

pep_sphinx_extensions/pep_processor/html/pep_html_builder.py

@@ -48,4 +48,4 @@ class DirectoryBuilder(FileBuilder):
     # sync all overwritten things from DirectoryHTMLBuilder
     name = DirectoryHTMLBuilder.name
     get_target_uri = DirectoryHTMLBuilder.get_target_uri
-    get_outfilename = DirectoryHTMLBuilder.get_outfilename
+    get_output_path = DirectoryHTMLBuilder.get_output_path

requirements.txt

@@ -3,10 +3,9 @@
 # Sphinx requires >= 2.17. JSON5 support added in 2.19, `lazy` highlight added in 2.21
 pygments >= 2.21
 
-# Sphinx 6.1.0 broke copying images in parallel builds; fixed in 6.1.2
-# See https://github.com/sphinx-doc/sphinx/pull/11100
-Sphinx >= 5.1.1, != 6.1.0, != 6.1.1, < 8.1.0
-docutils >= 0.19.0
+Sphinx >= 8.2
+# 0.22 causes build errors, see https://github.com/python/peps/issues/4924
+docutils < 0.22
 sphinx-notfound-page >= 1.0.2
 # For search
 pagefind[bin] >= 1.5.0