Fix QuboleHook unable to add list to tags (#9347)

airflow/providers/qubole/hooks/qubole.py

@@ -254,4 +254,4 @@ def _add_tags(tags, value):
         if isinstance(value, str):
             tags.add(value)
         elif isinstance(value, (list, tuple)):
-            tags.extend(value)
+            tags.update(value)

tests/providers/qubole/hooks/test_qubole.py

@@ -0,0 +1,40 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+import unittest
+
+from airflow.providers.qubole.hooks.qubole import QuboleHook
+
+add_tags = QuboleHook._add_tags
+
+
+class TestQuboleHook(unittest.TestCase):
+    def test_add_string_to_tags(self):
+        tags = {'dag_id', 'task_id'}
+        add_tags(tags, 'string')
+        self.assertEqual({'dag_id', 'task_id', 'string'}, tags)
+
+    def test_add_list_to_tags(self):
+        tags = {'dag_id', 'task_id'}
+        add_tags(tags, ['value1', 'value2'])
+        self.assertEqual({'dag_id', 'task_id', 'value1', 'value2'}, tags)
+
+    def test_add_tuple_to_tags(self):
+        tags = {'dag_id', 'task_id'}
+        add_tags(tags, ('value1', 'value2'))
+        self.assertEqual({'dag_id', 'task_id', 'value1', 'value2'}, tags)