TEMP: Use Ubuntu 20.04 for Python3.7

Author: AlexanderWells-diamond

.github/workflows/code.yml

@@ -15,7 +15,7 @@ jobs:
         install: ["-e .[dev]"]
         # Make one version be non-editable to test both paths of version code
         include:
-          - os: "ubuntu-22.04"
+          - os: "ubuntu-20.04"
             python: "3.7"
             install: ".[dev]"