sagemathgh-41141: Fix the compatibility issue for ipython 9.7.0
    
Remove the outdate unicode_to_str. Solve sagemath#41140
This function is mainly used to compatible for python2. Now it is gone.
It cause crash when run sage
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URL: sagemath#41141
Reported by: Chenxin Zhong
Reviewer(s): Dima Pasechnik

Author: Release Manager

src/sage/repl/display/formatter.py

@@ -62,7 +62,6 @@
 from io import StringIO
 
 from IPython.core.formatters import DisplayFormatter, PlainTextFormatter
-from IPython.utils.py3compat import unicode_to_str
 from IPython.core.display import DisplayObject
 
 from ipywidgets import Widget
@@ -311,7 +310,7 @@ def __call__(self, obj):
             print('---- calling ipython formatter ----')
         stream = StringIO()
         printer = SagePrettyPrinter(
-            stream, self.max_width, unicode_to_str(self.newline))
+            stream, self.max_width, self.newline)
         printer.pretty(obj)
         printer.flush()
         return stream.getvalue()