upgrade Sphinx to 8.2.1 release (#1011)

Author: jmckenna

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: 3.10.12
+          python-version: 3.13
 
       - name: Build docs
         run: |

requirements.txt

@@ -1,6 +1,6 @@
 alabaster==1.0.0
 docutils==0.21.2
-sphinx==8.1.3
+sphinx==8.2.1
 sphinx-copybutton==0.5.2
 sphinxcontrib-jquery==4.1
 --extra-index-url https://test.pypi.org/simple/