v1.40.3

Plots v1.40.3

Diff since v1.40.2

Merged pull requests:

• Road to plots 2.0 (#4866) (@isentropic)
• Added error messages in grid function for invalid values for heights and widths (#4902) (@Gythre-9)
• Document a few consts (#4907) (@sjkelly)
• fix PythonPlot backend (#4911) (@t-bltg)

Closed issues:

• [FR] grid function: Throw errors on bad settings (#4212)
• [FR] Make PythonPlot v1.0.3 compatible (#4841)
• [BUG] pythonplot backend not working: UndefVarError: pyisnone not defined (#4905)
• PythonCall.pyisnone() does not exist, please remove it from source code (#4906)