revert: undo a breaking test to attempt a cancelled workflow

Author: zimeg

tests/slack_bolt/context/test_say.py

@@ -22,7 +22,7 @@ def teardown_method(self):
     def test_say(self):
         say = Say(client=self.web_client, channel="C111")
         response: SlackResponse = say(text="Hi there!")
-        assert response.status_code == 404
+        assert response.status_code == 200
 
     def test_say_unfurl_options(self):
         say = Say(client=self.web_client, channel="C111")