gh-37808: Removed non-working and utterly old @rename_keyword in farey_symbol.pyx
See #37807 for discussion.
The keyword was renamed and is deprecated since 2013 : it is high-time
we get rid of the old version.
Besides, ``@rename_keyword`` does not work properly in Cython files (see
#37807 )
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URL: https://github.com/sagemath/sage/pull/37808
Reported by: SandwichGouda
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