gh-108765: Python.h no longer includes <ctype.h> (#108831)

Remove <ctype.h> in C files which don't use it; only sre.c and
_decimal.c still use it.

Remove _PY_PORT_CTYPE_UTF8_ISSUE code from pyport.h:

* Code added by commit b5047fd019
  in 2004 for MacOSX and FreeBSD.
* Test removed by commit 52ddaefb6b
  in 2007, since Python str type now uses locale independent
  functions like Py_ISALPHA() and Py_TOLOWER() and the Unicode
  database.

Modules/_sre/sre.c replaces _PY_PORT_CTYPE_UTF8_ISSUE with new
functions: sre_isalnum(), sre_tolower(), sre_toupper().

Remove unused includes:

* _localemodule.c: remove <stdio.h>.
* getargs.c: remove <float.h>.
* dynload_win.c: remove <direct.h>, it no longer calls _getcwd()
  since commit fb1f68ed7c (in 2001).

Include/pyport.h

@@ -392,44 +392,6 @@ extern "C" {
 #  define Py_NO_INLINE
 #endif
 
-/* On 4.4BSD-descendants, ctype functions serves the whole range of
- * wchar_t character set rather than single byte code points only.
- * This characteristic can break some operations of string object
- * including str.upper() and str.split() on UTF-8 locales.  This
- * workaround was provided by Tim Robbins of FreeBSD project.
- */
-
-#if defined(__APPLE__)
-#  define _PY_PORT_CTYPE_UTF8_ISSUE
-#endif
-
-#ifdef _PY_PORT_CTYPE_UTF8_ISSUE
-#ifndef __cplusplus
-   /* The workaround below is unsafe in C++ because
-    * the <locale> defines these symbols as real functions,
-    * with a slightly different signature.
-    * See issue #10910
-    */
-#include <ctype.h>
-#include <wctype.h>
-#undef isalnum
-#define isalnum(c) iswalnum(btowc(c))
-#undef isalpha
-#define isalpha(c) iswalpha(btowc(c))
-#undef islower
-#define islower(c) iswlower(btowc(c))
-#undef isspace
-#define isspace(c) iswspace(btowc(c))
-#undef isupper
-#define isupper(c) iswupper(btowc(c))
-#undef tolower
-#define tolower(c) towlower(btowc(c))
-#undef toupper
-#define toupper(c) towupper(btowc(c))
-#endif
-#endif
-
-
 /* Declarations for symbol visibility.
 
   PyAPI_FUNC(type): Declares a public Python API function and return type