Fix: File Browser: Filter for Annotations and Grease Pencil

The current filter was still using the legacy Grease Pencil
type (now Annotations).

Now this uses the correct `FILTER_ID_GP` and uses the
other filter for Annotations.

Pull Request: https://projects.blender.org/blender/blender/pulls/146978

source/blender/makesrna/intern/rna_ID.cc

@@ -126,6 +126,11 @@ const IDFilterEnumPropertyItem rna_enum_id_type_filter_items[] = {
     {FILTER_ID_CF, "filter_cachefile", ICON_FILE, "Cache Files", "Show Cache File data-blocks"},
     {FILTER_ID_CU_LEGACY, "filter_curve", ICON_CURVE_DATA, "Curves", "Show Curve data-blocks"},
     {FILTER_ID_GD_LEGACY,
+     "filter_annotations",
+     ICON_OUTLINER_DATA_GREASEPENCIL,
+     "Annotations",
+     "Show Annotation data-blocks"},
+    {FILTER_ID_GP,
      "filter_grease_pencil",
      ICON_GREASEPENCIL,
      "Grease Pencil",