Message 308561 - Python tracker

Oh. Another Python function is impacted by the bug, str.format:

$ env -i python3 -c 'import locale; locale.setlocale(locale.LC_ALL, "fr_FR"); locale.setlocale(locale.LC_NUMERIC, "es_MX.utf8"); print(ascii(f"{1000:n}"))'
'1\xe2\x80\x89000'

It should be '1\u2009000' ('1', '\u2009', '000').