Test with Python 3.10, drop 3.7

Author: michaelosthege

.github/workflows/pipeline.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9"]
+        python-version: ["3.8", "3.9", "3.10"]
     services:
       clickhouse:
         image: yandex/clickhouse-server