Fix #128916: Tag Light ID when applying scale

When applying scale on a light in the viewport, ensure we tag the light
itself for updating. Otherwise, the viewport get confused over which
size to use.

Pull Request: https://projects.blender.org/blender/blender/pulls/129030

source/blender/editors/object/object_transform.cc

@@ -1044,6 +1044,11 @@ static int apply_objects_internal(bContext *C,
       la->area_size *= rsmat[0][0];
       la->area_sizey *= rsmat[1][1];
       la->area_sizez *= rsmat[2][2];
+
+      /* Explicit tagging is required for Lamp ID because, unlike Geometry IDs like Mesh,
+       * it is not covered by the `ID_RECALC_GEOMETRY` flag applied to the object at the end
+       * of this loop. */
+      DEG_id_tag_update(&la->id, ID_RECALC_PARAMETERS);
     }
     else {
       continue;