dropping matplotlib down to 3.5.2
dropping matplotlib down to 3.5.2

- One of our sub dependencies uses it and compiling 3.5.3 is failing on
  some python versions
  https://github.com/matplotlib/matplotlib/issues/23604

OpenMined/PySyft,OpenMined/PySyft,OpenMined/PySyft,OpenMined/PySyft