test(backends): copy from_connection to new file

ibis/backends/tests/test_dbapi.py

@@ -0,0 +1,9 @@
+from __future__ import annotations
+
+CON_ATTR = {"flink": "_table_env"}
+DEFAULT_CON_ATTR = "con"
+
+
+def test_from_connection(con):
+    new_con = type(con).from_connection(getattr(con, CON_ATTR.get(con.name, "con")))
+    assert {"astronauts", "batting", "diamonds"} <= set(new_con.list_tables())