Revert "remove allow-prereleases: true"

This reverts commit cb279c9.

Author: parthea

.github/workflows/unittest.yml

@@ -34,6 +34,7 @@ jobs:
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python }}
+        allow-prereleases: true
     - name: Install nox
       run: |
         python -m pip install --upgrade setuptools pip wheel