Use older Ubuntu to test with Python 3.7

Author: benmwebb

.github/workflows/build.yml

@@ -9,7 +9,10 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-24.04]
-        python-version: ["3.7", "3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
+        include:
+        - os: ubuntu-22.04
+          python-version: '3.7'
     runs-on: ${{ matrix.os }}
 
     steps: