Add separate SZIP static lib path (to fix macos new link issue).

$ $JOB_PYTHON -c "import pyfaust; print(pyfaust.version()); print(pyfaust.rand(5,5).toarray());"

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Users/ci/builds/6uVWsSVY/0/faustgrp/faust/test_pyfaust-3.38.16/lib/python3.9/site-packages/pyfaust/__init__.py", line 142, in <module>
    import _FaustCorePy
ImportError: dlopen(/Users/ci/builds/6uVWsSVY/0/faustgrp/faust/test_pyfaust-3.38.16/lib/python3.9/site-packages/_FaustCorePy.cpython-39-darwin.so, 2): Symbol not found: _SZ_BufftoBuffCompress
  Referenced from: /Users/ci/builds/6uVWsSVY/0/faustgrp/faust/test_pyfaust-3.38.16/lib/python3.9/site-packages/_FaustCorePy.cpython-39-darwin.so
  Expected in: flat namespace
 in /Users/ci/builds/6uVWsSVY/0/faustgrp/faust/test_pyfaust-3.38.16/lib/python3.9/site-packages/_FaustCorePy.cpython-39-darwin.so