Skip Python 3.7 test on ubuntu-latest

Author: rayluo

.github/workflows/python-package.yml

@@ -20,6 +20,9 @@ jobs:
         python-version: [3.7, 3.8, 3.9, "3.10", 3.11, 3.12]
         os: [ubuntu-latest, windows-latest, macos-latest]
         exclude:  # https://github.com/actions/runner-images/issues/9770#issuecomment-2085623315
+          # ubuntu-latest dropped Python 3.7 since late 2024
+          - python-version: "3.7"
+            os: ubuntu-latest
           # Apple Silicon ARM64 does not support Python < v3.8
           - python-version: "3.7"
             os: macos-latest