orjson macosx wheels since 3.6.9 require unspecified recent macosx version (>=10.15)

[jefferis]

On a machine running 10.14 I see:

Error in py_module_import(module, convert = convert) : 
  ImportError: dlopen(/Users/jefferis/Library/r-miniconda/envs/r-reticulate/lib/python3.8/site-packages/orjson/orjson.cpython-38-darwin.so, 2): no suitable image found.  Did find:
	/Users/jefferis/Library/r-miniconda/envs/r-reticulate/lib/python3.8/site-packages/orjson/orjson.cpython-38-darwin.so: cannot load 'orjson.cpython-38-darwin.so' (load command 0x80000034 is unknown)
	/Users/jefferis/Library/r-miniconda/envs/r-reticulate/lib/python3.8/site-packages/orjson/orjson.cpython-38-darwin.so: cannot load 'orjson.cpython-38-darwin.so' (load command 0x80000034 is unknown)

Detailed traceback:
  File "/Library/Frameworks/R.framework/Versions/4.1/Resources/library/reticulate/python/rpytools/loader.py", line 39, in _import_hook
    module = _import(
  File "/Users/jefferis/Library/r-miniconda/envs/r-reticulate/lib/python3.8/site-packages/cloudvolume/__init__.py", line 49, in <module>
    from .cloudvolume import CloudVolume, register_plugin
  File "/Library/Frameworks/R.framework/Vers

The key error is

load command 0x80000034 is unknown

this corresponds to LC_DYLD_CHAINED_FIXUPS (see e.g. ronaldoussoren/macholib#31) which is not available on macosx 10.14. I think the macosx build environment should explicitly specify a lower target version.

Of the available binaries 3.6.8 is the last that works for me.

[ijl]

https://github.com/ijl/orjson/releases/tag/3.7.6