Update py side6 dependencies (#1639)

* - Removed PySide 2 requirement
- updates:
     - pyside6 >=6.5.0, <6.10
     - bw2data >=4.1

* Update requirements for pip as well:
- updates:
     - pyside6 >=6.5.0, <6.10
     - bw2data >=4.1

* -removing conda requirement for pyside6 again as conda-forge still does not have pyside6-addons. So PySide6 must still be installed via pip via an extra command if using conda for the AB

Author: bsteubing