read-tree + fetch tests: test failing "--super-prefix" interaction

read-tree + fetch tests: test failing "--super-prefix" interaction

Ever since "git fetch --refetch" was introduced in 0f5e8851737 (Merge
branch 'rc/fetch-refetch', 2022-04-04) the test being added here would
fail. This is because "restore" will "read-tree .. --reset <hash>",
which will in turn invoke "fetch". The "fetch" will then die with:

	fatal: fetch doesn't support --super-prefix

This edge case and other "--super-prefix" bugs will be fixed in
subsequent commits, but let's first add a "test_expect_failure" test
for it. It passes until the very last command in the test.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>