py/persistentcode: Bump .mpy sub-version to 6.3.

This is required because the .mpy native ABI was changed by the
introduction of `mp_proto_fun_t`, see commits:
- 416465d81e
- 5e3006f117
- e2ff00e811

And three `mp_binary` functions were added to `mp_fun_table` in
commit d2276f0d41.

Signed-off-by: Damien George <damien@micropython.org>

tools/mpy_ld.py

@@ -36,7 +36,7 @@ import makeqstrdata as qstrutil
 
 # MicroPython constants
 MPY_VERSION = 6
-MPY_SUB_VERSION = 2
+MPY_SUB_VERSION = 3
 MP_CODE_BYTECODE = 2
 MP_CODE_NATIVE_VIPER = 4
 MP_NATIVE_ARCH_X86 = 1