Add first Gitaly acceptance test

See merge request gitlab-org/gitlab-shell!475

fix: upgrade of the labkit dependency

See merge request gitlab-org/gitlab-shell!474

The labkit has a fix in the dependency chain b36f912 (Merge branch 'ps-fix-dep-version' into 'master', 2021-05-20).

1.4.0 has introduced the format change
Since v1 means latest 1.* image, we're pulling the unsupported version

Acceptance tests for 2fa_recovery_codes, 2fa_verify, and git-lfs-authenticate

See merge request gitlab-org/gitlab-shell!472

Add acceptance test for personal_access_token command

See merge request gitlab-org/gitlab-shell!471

Respect parent context for Gitaly calls

See merge request gitlab-org/gitlab-shell!469

Stop changing directory to the filesystem root

See merge request gitlab-org/gitlab-shell!470

This behaviour dates from when Gitaly RPCs were executed in Ruby by a
Go subprocess. It's not needed for gitlab-shell now that it's in Go,
and it's a very strange thing for gitlab-sshd. Best just to remove it.

If we wanted to retain this behaviour, we could have an `os.Chdir` call
in the gitlab-shell binary, but I just don't think it's needed.

Changelog: fixed

Without these changes, Gitaly calls would not be linked to a parent
context. This means that they would have an unassociated correlationID,
and Gitaly RPC calls would not be cancel()ed by parent context
cancellation.

Changelog: fixed

Update LabKit to v1.4.0

Closes #478

See merge request gitlab-org/gitlab-shell!468

gitlab-sshd: Respect the ssl_cert_dir config

Closes #516

See merge request gitlab-org/gitlab-shell!467

Don't finish the opentracing span early

See merge request gitlab-org/gitlab-shell!466

Changelog: fixed

Calling finished() in `ContextWithCorrelationID` breaks opentracing,
since it expects us to call it just before exiting, and this defer
runs on function completion.

All existing users of ContextWithCorrelationID already `defer finish()`
themselves, so this call is entirely surplus to requirements.

Release v13.18.0

See merge request gitlab-org/gitlab-shell!465

sshd: Recover from per-session and per-connection panics

Closes #511

See merge request gitlab-org/gitlab-shell!464

Without this, a failure in a single session could take out a whole
connection, or a failure in a single connection could take out the
whole server.

Extract sshd connections and sessions into their own files and structs

See merge request gitlab-org/gitlab-shell!463

gitlab-sshd: Support the PROXY protocol

Closes #491 and gitlab-com/gl-infra/infrastructure#10954

See merge request gitlab-org/gitlab-shell!461

Fix thread-safety issues in gitlab-shell

Closes #518

See merge request gitlab-org/gitlab-shell!462

Replace cleanup functions with t.Cleanup

See merge request gitlab-org/gitlab-shell!460

In this case we don't need to propagate cleanup
function. It simplifies the code.

gitlab-sshd: Acceptance test for the discover command

See merge request gitlab-org/gitlab-shell!457

With this, we can start to build confidence in making changes to
gitlab-sshd.

chore: Move environment introspection to sshenv module

See merge request gitlab-org/gitlab-shell!451

Refactors introspection of execution environment to rely on
per-connection state (`gitlab-shell`) or per request (`gitlab-sshd`)

Relates to https://gitlab.com/gitlab-org/gitlab-shell/-/issues/496