ci: pin python-version we use to generate the published spec

Some dependencies we need do not yet have wheels available for Python 3.11
which is installed by the '3.x' version selector.

Signed-off-by: Joshua Lock <[email protected]>

Author: joshuagl

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@b55428b1882923874294fa556849718a1d7f2ca5
       with:
-        python-version: 3.x
+        python-version: '3.10'
         cache: 'pip'
 
     - name: Get previous version