cubicweb-leaflet #4514690 data/leafletcluster is not packaged in source dist [validation pending]

Fix __pkginfo__.py to include it.

prioritynormal
typebug
done in0.2.1
load0.100
load left0.000
closed by#a5f0ef6f2a6c include data/leafletcluster in source distribution (closes #4514690)
patchinclude data/leafletcluster in source distribution (closes #4514690) [applied]