Bug#1064028: libpython3.12-dev: non-C90 headerfile code breaks -Werror=declaration-after-statement

[James Addison]

Followup-For: Bug #1064028
Control: tags -1 fixed-upstream
Control: forwarded -1 https://github.com/python/cpython/issues/116869 
https://github.com/python/cpython/pull/117011