Set up Python for Azure Managed tests

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 61acbc5e-7c07-42a7-8e38-31329c4befce

Author: andystaples

.github/workflows/durabletask-azuremanaged.yml

@@ -40,6 +40,11 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
       - name: Install Nox
         run: |
           python -m pip install --upgrade pip