removed mpi

docs/requirements.txt

 # Defining the exact version will make sure things don't break
-libopenmpi-dev
 sphinx==5.3.0
 sphinx_rtd_theme==1.1.1
 readthedocs-sphinx-search==0.1.1
@@ -7,7 +6,6 @@ numpy>=1.21
 pandas>=1.5.3
 scipy>=1.7
 h5py>=3.6
-mpi4py>=3.1
 matplotlib>=3.5
 seaborn>=0.12
 mpmath>=1.2.1