add python 3.13 to test CI

Author: Michael-J-Ward

.github/workflows/test.yaml

@@ -36,6 +36,7 @@ jobs:
           - "3.10"
           - "3.11"
           - "3.12"
+          - "3.13"
         toolchain:
           - "stable"
 
@@ -101,6 +102,13 @@ jobs:
           source venv/bin/activate
           pip install -r requirements-311.txt
 
+      - name: Create Virtualenv (3.13)
+        if: ${{ matrix.python-version == '3.13' }}
+        run: |
+          python -m venv venv
+          source venv/bin/activate
+          pip install -r requirements-313.txt
+
       - name: Run tests
         env:
           RUST_BACKTRACE: 1