submodule--helper: remove unused SUPPORT_SUPER_PREFIX flags
Remove the SUPPORT_SUPER_PREFIX flag from "add", "init" and "summary". For the "add" command it hasn't been used since [1], likewise for "init" and "summary" since [2] and [3], respectively. As implemented in 74866d75793 (git: make super-prefix option, 2016-10-07) the SUPPORT_SUPER_PREFIX flag in git.c applies for the entire command, but as implemented in 89c86265576 (submodule helper: support super prefix, 2016-12-08) we assert here in cmd_submodule__helper() that we're not getting the flag unexpectedly. 1. 8c8195e9c3e (submodule--helper: introduce add-clone subcommand, 2021-07-10) 2. 6e7c14e65c8 (submodule update --init: display correct path from submodule, 2017-01-06) 3. 1cf823d8f00 (submodule: remove unnecessary `prefix` based option logic, 2021-06-22) Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Glen Choo <chooglen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>