COMP: Change binder Qt dep from PyQt5 QtPy to PySide2

PySid2 is licensed under the LGPL while PyQt5 is under the GPL and a
commercial license.

I could not successfully install the previous PyQt5 given versions
on Linux with Python 3.11.

Author: thewtex

.binder/requirements.txt

@@ -8,8 +8,6 @@ numpy
 torch>=2.0
 monai>=1.2.0
 matplotlib==3.3.1
-PyQt5==5.15.0
-PyQt5-sip==12.8.0
-QtPy==1.9.0
+PySide2
 voila
 tqdm