💚 Fix test matrix for Python 3.7 (#1116)

Author: svlandeg

.github/workflows/test.yml

@@ -22,7 +22,7 @@ jobs:
         os: [ ubuntu-latest, windows-latest, macos-latest ]
         python-version: [ "3.12" ]
         include:
-          - os: ubuntu-latest
+          - os: ubuntu-22.04
             python-version: "3.7"
           - os: macos-latest
             python-version: "3.8"