chore: remove ANSI color codes from warning messages (#1498)

* chore: remove ANSI color codes from warning messages

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: chelsea-lin

bigframes/exceptions.py

@@ -95,11 +95,6 @@ class ObsoleteVersionWarning(Warning):
     """The BigFrames version is too old."""
 
 
-class ColorFormatter:
-    WARNING = "\033[93m"
-    ENDC = "\033[0m"
-
-
 def format_message(message: str, fill: bool = True):
     """Formats a warning message with ANSI color codes for the warning color.
 
@@ -110,10 +105,9 @@ def format_message(message: str, fill: bool = True):
             especially if the message already contains newlines.
 
     Returns:
-        The formatted message string, with ANSI color codes for warning color
-        if color is supported, otherwise the original message.  If `fill` is
-        True, the message will be wrapped to fit the terminal width.
+        The formatted message string. If `fill` is True, the message will be wrapped
+        to fit the terminal width.
     """
     if fill:
         message = textwrap.fill(message)
-    return ColorFormatter.WARNING + message + ColorFormatter.ENDC
+    return message