Revert "RNA define: check and report invalid usages of ID pointers properties."

This reverts commit f39fbb3e60.

Code is not valid, `DefRNA.laststruct` does not always point to the
proper struct when defined from Python, need to be done differently.

source/blender/makesrna/intern/rna_define.c

@@ -1823,13 +1823,6 @@ void RNA_def_property_struct_runtime(PropertyRNA *prop, StructRNA *type)
 
   switch (prop->type) {
     case PROP_POINTER: {
-      if ((srna->flag & STRUCT_NO_DATABLOCK_IDPROPERTIES) != 0 && (type->flag & STRUCT_ID) != 0) {
-        CLOG_ERROR(&LOG,
-                   "Struct \"%s\" (probably an operator or keymap) does not allow pointer "
-                   "properties to ID datablocks.",
-                   srna->identifier);
-        return;
-      }
       PointerPropertyRNA *pprop = (PointerPropertyRNA *)prop;
       pprop->type = type;