convert facecolors to nparray

Summary:

This is a fix for a bug while trying to create extra_geom assembled plot

Report:

AGIPDCharacterizeDarkImages.pdf

Reviewers:

@danilevc @kamile

cal_tools/cal_tools/plotting.py

@@ -275,7 +275,7 @@ def show_processed_modules(dinstance: str, constants: Optional[Dict[str, Any]],
 
     # Set each tile colour individually, extra_geom provides a single color
     # for all tiles.
-    facecolors = np.array(tiles.get_facecolors().tolist() * tile_count)
+    facecolors = np.repeat(tiles.get_facecolor(), tile_count, axis=0)
 
     # Set module name fonts
     for text in ax.texts: