Retiring support for older python versions

Author: jamesridgway

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.7, 3.8, 3.9, 3.11]
+        python-version: [3.11, 3.12, 3.13]
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}