Sliceviewer cursor tracking fix for MDHistograms ornl-next

Quiet python warnings on startup of workbench (ornlnext)

Change workflow diagrams from `.png` to `.svg` (ornlnext)

This makes them scale better in web browsers and smaller on disk.

Merged along with #32010. 

These are minor issues having to do with types (yes, I know it is
python) and leaving dangling file references.

Scd369 expand integrate ellipesoid

Remove qt4 dependency from developer packages

Since mantidplot is no longer in the codebase, the dependencies are no
longer needed by developers.