fix: Avoid querying database version when executing client queries

appmap/django.py

@@ -117,6 +117,11 @@ def wrapped_execute(self, sql, params=None):
 @receiver(connection_created)
 def connected(sender, connection, **_):
     # pylint: disable=unused-argument
+
+    # warm the version cache in the backend to avoid running
+    # additional queries in the middle of processing client queries
+    database_version(connection)
+
     wrappers = connection.execute_wrappers
     if not any(isinstance(x, ExecuteWrapper) for x in wrappers):
         wrappers.append(ExecuteWrapper())

ci/smoketest.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 set -e
-pip install -U pip pytest flask python-decouple
+pip install -U pip pytest "flask<2" python-decouple
 pip install /dist/appmap-*-py3-none-any.whl
 
 cp -R /appmap/test/data/unittest/simple ./.