incorrect channel scaling in default plotting

[sophiamaedler]

the overlayed microscopy images are scaled incorrectly where as individual channels are plotted as expected.

[sophiamaedler]

see scverse/spatialdata-plot#507

[sophiamaedler]

temporarily patch in scPortrait by limiting spatial data-plot<0.2.11

[sophiamaedler]

Issue is fixed in the following PR: scverse/spatialdata-plot#520

Once merged into a new release can update spatialdata-plot version.

[sophiamaedler]

new release of spatialdata-plot has been made with the fix implemented