Merge pull request #1076 from sphinx-contrib/add-py313-to-build-workflow

workflows: test against python 3.13

Author: jdknight

.github/workflows/build.yml

@@ -53,6 +53,11 @@ jobs:
             - { os:  ubuntu-latest, python: "3.12", toxenv: py312-sphinx74, cache: ~/.cache/pip }
             - { os:  ubuntu-latest, python: "3.12", toxenv: py312-sphinx80, cache: ~/.cache/pip }
             - { os:  ubuntu-latest, python: "3.12", toxenv: py312-sphinx81, cache: ~/.cache/pip }
+            - { os:  ubuntu-latest, python: "3.13", toxenv: py313-sphinx72, cache: ~/.cache/pip }
+            - { os:  ubuntu-latest, python: "3.13", toxenv: py313-sphinx73, cache: ~/.cache/pip }
+            - { os:  ubuntu-latest, python: "3.13", toxenv: py313-sphinx74, cache: ~/.cache/pip }
+            - { os:  ubuntu-latest, python: "3.13", toxenv: py313-sphinx80, cache: ~/.cache/pip }
+            - { os:  ubuntu-latest, python: "3.13", toxenv: py313-sphinx81, cache: ~/.cache/pip }
 
             # other OSes
             #  - test against all other supported OSes, using most recent interpreter/sphinx