gh-136087: Remove \r from documented os.linesep values (#136088)

Author: sobolevn

Lib/os.py

@@ -10,7 +10,7 @@
   - os.extsep is the extension separator (always '.')
   - os.altsep is the alternate pathname separator (None or '/')
   - os.pathsep is the component separator used in $PATH etc
-  - os.linesep is the line separator in text files ('\r' or '\n' or '\r\n')
+  - os.linesep is the line separator in text files ('\n' or '\r\n')
   - os.defpath is the default search path for executables
   - os.devnull is the file path of the null device ('/dev/null', etc.)