Remove non-existent files from MANIFEST.in (#9752)

* remove qiskit/schemas

* remove include cython files

* remove include pickle files

MANIFEST.in

@@ -1,17 +1,12 @@
 include LICENSE.txt
 include requirements.txt
 include qiskit/qasm/libs/*.inc
-include qiskit/schemas/*.json
-include qiskit/schemas/examples/*.json
 include qiskit/VERSION.txt
-recursive-include qiskit *.pyx
-recursive-include qiskit *.pxd
 include qiskit/visualization/circuit/styles/*.json
 recursive-include qiskit/providers/fake_provider/backends *.json
 
 # Include the tests files.
 recursive-include test *.py
-include test/python/pickles/*.pickle
 include test/python/qasm/*.qasm
 include test/python/visualization/references/*.png
 include test/python/notebooks/*.ipynb