CI: Stop testing on Python 3.7, 3.8, 3.9

Author: amotl

.github/workflows/tests.yml

@@ -20,7 +20,12 @@ jobs:
     strategy:
       matrix:
         os: ['ubuntu-22.04']
-        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12', '3.13', '3.14']
+        python-version:
+          - '3.10'
+          - '3.11'
+          - '3.12'
+          - '3.13'
+          - '3.14'
         cratedb-version: ['nightly']
         sqla-version: ['<1.4', '<1.5', '<2.1']
         pip-allow-prerelease: ['false']