0.23.0: build breakage with zstd 1.5.7

[0-wiz-0]

When trying to compile release 0.23.0 having zstd 1.5.7 installed, I see

build/zstandard/_cffi.c: In function '_cffi_const_ZSTD_c_useBlockSplitter':
build/zstandard/_cffi.c:12168:12: error: 'ZSTD_c_useBlockSplitter' undeclared (first use in this function); did you mean 'ZSTD_c_maxBlockSize'?
12168 |   int n = (ZSTD_c_useBlockSplitter) <= 0;
      |            ^~~~~~~~~~~~~~~~~~~~~~~
      |            ZSTD_c_maxBlockSize

This parameter was removed in 1.5.7.

[hhoffstaette]

This was changed in facebook/zstd#4180 - ZSTD_c_useBlockSplitter was an experimental parameter that never should have been used.

[jjerphan]

To understand why this fails, see:

python-zstandard/c-ext/backend_c.c

Lines 137 to 151 in 0063333

	/* python-zstandard relies on unstable zstd C API features. This means
	that changes in zstd may break expectations in python-zstandard.
	python-zstandard is distributed with a copy of the zstd sources.
	python-zstandard is only guaranteed to work with the bundled version
	of zstd.
	However, downstream redistributors or packagers may unbundle zstd
	from python-zstandard. This can result in a mismatch between zstd
	versions and API semantics. This essentially "voids the warranty"
	of python-zstandard and may cause undefined behavior.
	We detect this mismatch here and refuse to load the module if this
	scenario is detected.
	*/

.