Update documentation of PyUnicode_DecodeFSDefault(),
PyUnicode_DecodeFSDefaultAndSize() and PyUnicode_EncodeFSDefault():
they now use the filesystem encoding and error handler of PyConfig,
Py_FileSystemDefaultEncoding and Py_FileSystemDefaultEncodeErrors
variables are no longer used.

Deprecate global configuration variables, like
Py_IgnoreEnvironmentFlag, in the documentation: the
Py_InitializeFromConfig() API should be instead.

Deprecate global configuration variables, like
Py_IgnoreEnvironmentFlag, in the documentation: the
Py_InitializeFromConfig() API should be instead.

Update documentation of PyUnicode_DecodeFSDefault(),
PyUnicode_DecodeFSDefaultAndSize() and PyUnicode_EncodeFSDefault():
they now use the filesystem encoding and error handler of PyConfig,
Py_FileSystemDefaultEncoding and Py_FileSystemDefaultEncodeErrors
variables are no longer used.

…Flag

* Replace deprecated Py_DebugFlag with PyConfig.parser_debug in the
  parser.
* Add Parser.debug member.
* Add tok_state.debug member.
* Py_FrozenMain(): Replace Py_VerboseFlag with PyConfig.verbose.

…93106)

* Replace deprecated Py_DebugFlag with PyConfig.parser_debug in the
  parser.
* Add Parser.debug member.
* Add tok_state.debug member.
* Py_FrozenMain(): Replace Py_VerboseFlag with PyConfig.verbose.

Document that -d option and PYTHONDEBUG env var requires a debug
build of Python. Also mention them in the debug build documentation.

Document that -d option and PYTHONDEBUG env var require a debug
build of Python. Also mention them in the debug build documentation.

The Py_DecodeLocale() and Py_EncodeLocale() now use
_PyRuntime.preconfig, rather than Py_UTF8Mode and
Py_LegacyWindowsFSEncodingFlag global configuration varibles, to
decide if the UTF-8 encoding is used or not.

As documented, these functions must not be called before Python is
preinitialized. The new PyConfig API should now be used, rather than
using deprecated functions like Py_SetPath() or PySys_SetArgv().

The C API documentation now uses the new PyConfig API, rather than
deprecated global configuration variables.

The C API documentation now uses the new PyConfig API, rather than
deprecated global configuration variables.

…#96070)

The C API documentation now uses the new PyConfig API, rather than
deprecated global configuration variables.