Windows install: Added GtkSource-5.typelib (Inkscape 1.5)
MR !4885 (merged) introduced GtkSourceView to enable syntax highlighting in Inkscape's XML-editor. It would be nice if this library could also be used by Python extension developers to offer Syntax-Highlighting (like me for TexText).
For this to work the corresponding GtkSOurce-5.typelib (required by the GObject
introspection) is missing in Windows installations.
The patch adds only a single file of ca. 70 kB to the Windows installer, so this should be acceptable.
Linux installations are not affected since GtkSourceView is a package dependency of Inkscape, hence the typelib is available there. Same should hold for MacOS.