Bump sphinx version to >=5

gmelikov · web-flow · commit 24b6ab04d2f1 · 2023-08-30T21:14:23.000+03:00
Otherwise CI may have older preinstalled 2.4.4 and fail.
diff --git a/docs/requirements.txt b/docs/requirements.txt
@@ -1,4 +1,4 @@
-Sphinx
+sphinx>=5
 sphinx-issues
 sphinx-notfound-page>=0.5
 sphinx-rtd-theme
