py/obj: Remove the legacy object API for version 2.

These were changed in v1.11 (2019).  Prepare to remove the compatibility
macros as part of V2 changes.

This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>

py/obj.h

@@ -1273,6 +1273,8 @@ mp_obj_t mp_seq_extract_slice(const mp_obj_t *seq, mp_bound_slice_t *indexes);
     memmove(((char *)dest) + (beg + slice_len) * (item_sz), ((char *)dest) + (end) * (item_sz), ((dest_len) + (len_adj) - ((beg) + (slice_len))) * (item_sz)); \
     memmove(((char *)dest) + (beg) * (item_sz), slice, slice_len * (item_sz));
 
+#if !MICROPY_PREVIEW_VERSION_2
+
 // Provide translation for legacy API
 #define MP_OBJ_IS_SMALL_INT mp_obj_is_small_int
 #define MP_OBJ_IS_QSTR mp_obj_is_qstr
@@ -1285,4 +1287,6 @@ mp_obj_t mp_seq_extract_slice(const mp_obj_t *seq, mp_bound_slice_t *indexes);
 #define MP_MAP_SLOT_IS_FILLED mp_map_slot_is_filled
 #define MP_SET_SLOT_IS_FILLED mp_set_slot_is_filled
 
+#endif
+
 #endif // MICROPY_INCLUDED_PY_OBJ_H