Docs: bump sphinx version

[ci skip]

Author: WardBrian

.github/workflows/release.yml

@@ -32,13 +32,13 @@ jobs:
 
       - name: Install dependencies (python)
         run: |
-          python -m pip install --upgrade pip wheel twine codecov "sphinx>4,<5" nbsphinx ipython ipykernel "pydata-sphinx-theme<0.9" requests sphinx-copybutton xarray matplotlib
+          python -m pip install --upgrade pip wheel twine codecov "sphinx>5,<6" nbsphinx ipython ipykernel "pydata-sphinx-theme<0.9" requests sphinx-copybutton xarray matplotlib
           pip install -r requirements.txt
           pip install -e .
 
       - name: Install CmdStan
         run: |
-          python -m cmdstanpy.install_cmdstan
+          python -m cmdstanpy.install_cmdstan --verbose --cores 4
 
       - name: Setup git identity
         run: |

docsrc/env.yml

@@ -10,7 +10,7 @@ dependencies:
   - numpy>=1.15
   - pandas
   - xarray
-  - sphinx>4,<5
+  - sphinx>5,<6
   - nbsphinx
   - pydata-sphinx-theme>0.7,<0.9
   - sphinx-copybutton