Fix: Importer can fail with blender file browser recursive option enabled

The files property, provided by the blender file browser, contain
paths relative to the directory property. Use that instead of using
the filepath parent directory.

scripts/addons_core/io_scene_gltf2/__init__.py

@@ -5,7 +5,7 @@
 bl_info = {
     'name': 'glTF 2.0 format',
     'author': 'Julien Duroure, Scurest, Norbert Nopper, Urs Hanselmann, Moritz Becher, Benjamin Schmithüsen, Jim Eckerlein, and many external contributors',
-    "version": (4, 5, 46),
+    "version": (4, 5, 47),
     'blender': (4, 4, 0),
     'location': 'File > Import-Export',
     'description': 'Import-Export as glTF 2.0',
@@ -1851,6 +1851,11 @@ class ImportGLTF2(Operator, ConvertGLTF2_Base, ImportHelper):
 
     filter_glob: StringProperty(default="*.glb;*.gltf", options={'HIDDEN'})
 
+    directory: StringProperty(
+        subtype='DIR_PATH',
+        options={'HIDDEN', 'SKIP_PRESET'},
+    )
+
     files: CollectionProperty(
         name="File Path",
         type=bpy.types.OperatorFileListElement,
@@ -2028,9 +2033,8 @@ class ImportGLTF2(Operator, ConvertGLTF2_Base, ImportHelper):
         if self.files:
             # Multiple file import
             ret = {'CANCELLED'}
-            dirname = os.path.dirname(self.filepath)
             for file in self.files:
-                path = os.path.join(dirname, file.name)
+                path = os.path.join(self.directory, file.name)
                 if self.unit_import(path, import_settings) == {'FINISHED'}:
                     ret = {'FINISHED'}
             return ret