Update requirements.txt for humble branch

.github/workflows/deploy.yml

@@ -36,7 +36,7 @@ jobs:
 
     - uses: ruby/setup-ruby@v1
       with:
-        ruby-version: '2.7'
+        ruby-version: '3'
 
     - name: Run htmlproofer.sh
       run: ./htmlproofer.sh

conf.py

@@ -58,7 +58,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = "en"
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.

requirements.txt

@@ -1,7 +1,7 @@
 pip
-docutils==0.16
-sphinx==4.3.2
-sphinx-tabs
+docutils==0.18.1
+sphinx>=5.0.0
+sphinx-tabs==3.4.4
 sphinx-multiversion
 sphinx-rtd-theme
 sphinx-copybutton