patch 9.1.1580: possible memory leak in vim9type.c

patch 9.1.1580: possible memory leak in vim9type.c

Problem:  possible memory leak in vim9type.c
Solution: Free tuple_types_ga if there was an error in
          type_type_add_types() (Lidong Yan)

In parse_type_tuple() at src/vim9type.c, we allocate memory
in `tuple_types_ga` by ga_grow(), but forget to free it when
tuple_type_add_types() fails. Replace `return NULL` with `goto on_err`
to fix leak.

closes: #17820

Signed-off-by: Lidong Yan <yldhome2d2@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>