Issue#6959 :Updated Automatically generated rust files. (#7425)

* test

* only rust files

* updated idl_gen_rust.cpp

tests/arrays_test/my_game/example/array_struct_generated.rs

@@ -1,4 +1,5 @@
 // automatically generated by the FlatBuffers compiler, do not modify
+// @generated
 extern crate alloc;
 extern crate flatbuffers;
 use alloc::boxed::Box;