fix(clickhouse): use a context manager for execution

Ensure we properly disconnect when an error occurs.

ibis/backends/clickhouse/__init__.py

@@ -161,12 +161,13 @@ def raw_sql(
             )
 
         ibis.util.log(query)
-        return self.con.execute(
-            query,
-            columnar=True,
-            with_column_types=True,
-            external_tables=external_tables_list,
-        )
+        with self.con as con:
+            return con.execute(
+                query,
+                columnar=True,
+                with_column_types=True,
+                external_tables=external_tables_list,
+            )
 
     def fetch_from_cursor(self, cursor, schema):
         data, _ = cursor

pyproject.toml

@@ -160,12 +160,12 @@ addopts = [
 filterwarnings = [
   # fail on any warnings that are not explicitly matched below
   "error",
+  # pyspark and impala leave sockets open
+  "ignore:Exception ignored in:",
   # Future warning from analytics.py
   "ignore:ibis.expr.analytics will be removed in ibis 3.0",
   # poetry
   "ignore:distutils Version classes are deprecated:DeprecationWarning",
-  # clickhouse sockets aren't closed by sqlalchemy when running tests in parallel
-  'ignore:Exception ignored in:',
   # older importlib metadata that there's no real point in breaking with
   "ignore:SelectableGroups:DeprecationWarning",
   # geopandas warning