reduce line length

Co-authored-by: AN Long <aisk@users.noreply.github.com>

Author: Yuheng3107

Doc/library/readline.rst

@@ -9,7 +9,8 @@
 
 .. note::
    The new :term:`REPL` introduced in version 3.13 doesn't support readline.
-   However, readline can still be used by setting the :envvar:`PYTHON_BASIC_REPL` environment variable.
+   However, readline can still be used by setting the :envvar:`PYTHON_BASIC_REPL`
+   environment variable.
 
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