[issue33015] Fix function cast warning in thread_pthread.h

[STINNER Victor]

STINNER Victor <vstinner at redhat.com> added the comment:

The GCC warning is:

func_cast.c:34:30: warning: cast between incompatible function types from 'python_callback' {aka 'void (*)(void *)'} to 'void * (*)(void *)' [-Wcast-function-type]
     pthread_callback func2 = (pthread_callback)func;
                              ^

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue33015>
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