Qtpy refactor

[mrariden]

Replace PyQt5 dependency with more flexible qtpy library.

Test on:

• OS testing
  • Windows
  • Mac
  • Linux
• implement pip install logic to look if a pyqt install exists (check with rastermap/setup.py)
• Test uninstall pyqt5 followed upgrade pyqt6

[codecov]

Codecov Report

Merging #760 (17a57fc) into main (be14e5f) will increase coverage by 0.10%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##             main     #760      +/-   ##
==========================================
+ Coverage   63.26%   63.36%   +0.10%     
==========================================
  Files          14       14              
  Lines        2962     2962              
==========================================
+ Hits         1874     1877       +3     
+ Misses       1088     1085       -3     

Files Changed	Coverage Δ
cellpose/io.py	63.25% <50.00%> (ø)

... and 1 file with indirect coverage changes

[mrariden]

codecov is upset about decreased coverage, but tests are passing.

GUI test on ubuntu linux works for me

[mrariden]

I updated the install to use pyqt6 but allow pyqt5. I was getting an error related to qt not finding a dependency:

qt.core.plugin.loader: QLibraryPrivate::loadPlugin failed on "/<...>/site-packages/PyQt6/Qt6/plugins/platforms/libqxcb.so" : "Cannot load library /<...>/site-packages/PyQt6/Qt6/plugins/platforms/libqxcb.so: (libxcb-cursor.so.0: cannot open shared object file: No such file or directory)"
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: vkkhrdisplay, wayland-egl, wayland, minimal, eglfs, offscreen, minimalegl, linuxfb, xcb, vnc.

Aborted (core dumped)

which I fixed by finding the missing package using ldd where the libqxcb.so file was to identify packages that weren't found. Finally sudo apt install libxcb-cursor-dev solved the issue.

Not sure how big of an issue that will be for other linux users