Don't error when (un)pausing (un)paused dag in the CLI (apache#38585)

If we find that the dag is unpaused already, we should just inform
the user instead of raising error. Same with pausing

airflow/cli/commands/dag_command.py

@@ -230,7 +230,8 @@ def set_is_paused(is_paused: bool, args) -> None:
     ]
 
     if not dags:
-        raise AirflowException(f"No {'un' if is_paused else ''}paused DAGs were found")
+        print(f"No {'un' if is_paused else ''}paused DAGs were found")
+        return
 
     if not args.yes and args.treat_dag_id_as_regex:
         dags_ids = [dag.dag_id for dag in dags]

tests/cli/commands/test_dag_command.py

@@ -707,10 +707,20 @@ def test_pause_non_existing_dag_error(self):
         with pytest.raises(AirflowException):
             dag_command.dag_pause(args)
 
-    def test_unpause_already_unpaused_dag_error(self):
+    def test_unpause_already_unpaused_dag_do_not_error(self):
         args = self.parser.parse_args(["dags", "unpause", "example_bash_operator", "--yes"])
-        with pytest.raises(AirflowException, match="No paused DAGs were found"):
+        with contextlib.redirect_stdout(StringIO()) as temp_stdout:
             dag_command.dag_unpause(args)
+            out = temp_stdout.getvalue().strip().splitlines()[-1]
+        assert out == "No paused DAGs were found"
+
+    def test_pausing_already_paused_dag_do_not_error(self):
+        args = self.parser.parse_args(["dags", "pause", "example_bash_operator", "--yes"])
+        with contextlib.redirect_stdout(StringIO()) as temp_stdout:
+            dag_command.dag_pause(args)
+            dag_command.dag_pause(args)
+            out = temp_stdout.getvalue().strip().splitlines()[-1]
+        assert out == "No unpaused DAGs were found"
 
     def test_trigger_dag(self):
         dag_command.dag_trigger(