Avoid vertical_overflow='visible'

When this is set and content that has been scrolled gets updated, it gets erroneously duplicated

Author: cpsievert

chatlas/_display.py

@@ -46,7 +46,6 @@ def __init__(self, echo_options: "EchoOptions"):
         self.content: str = ""
         self.live = Live(
             auto_refresh=False,
-            vertical_overflow="visible",
             console=Console(
                 **echo_options["rich_console"],
             ),