Use GIX_TEST_FIXTURE_HASH for more tests

[Christoph Rüßler (cruessler)]

This PR adds explicit test runs under GIX_TEST_FIXTURE_HASH=sha1 and GIX_TEST_FIXTURE_HASH=sha256 for the following crates:

• gix-dir
• gix-fsck
• gix-negotiate

This PR follows the example from this commit and earlier ones: 4a0ca97 (merged in #2893).

This is part of a series of PRs where I try to find crates that pass their tests under GIX_TEST_FIXTURE_HASH=sha1, but not yet under GIX_TEST_FIXTURE_HASH=sha256.

[Sebastian Thiel (Byron)]

Thanks a lot!

When looking at the justfile (whose edits were following the usual pattern) I kept thinking that the cargo nextest run --no-fail-fast probably already runs a bunch of SHA-256 tests due to the way it compiles everything at once, with all features. But then again, if it would have, it would have failed. In any case, I thought it would at least run the SHA-1 tests. From there I wonder if the separate SHA-1 invocations of the individual crates are still needed.
Maybe something to investigate the next time the file is edited.

[Christoph Rüßler (cruessler)]

I was wondering the same. I added the GIX_TEXT_FIXTURE_HASH=sha1 lines mostly for consistency. I’m going to double-check whether some of them can be removed.