CI: make sure version works without -dev

.github/workflows/ci_tests.yml

@@ -113,6 +113,7 @@ jobs:
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python }}
+        allow-prereleases: true
     - name: Install base dependencies
       run: python -m pip install --upgrade pip setuptools tox
     - name: Print Python, pip, setuptools, and tox versions