Retry CI trace archive if left in incomplete state

What does this MR do?

This aims to remove fix some of the cases that could allow Ci::Builds to have both a live trace & and archived trace.

What is changing?

The code change here allows an archived_trace that is incomplete to be removed, and rebuilt in a single run of Ci::Trace#unsafe_archive!. Previously, we would remove the archived_trace and raise an AlreadyArchivedError without rebuilding the archive file.

Scenario	Previous	New
trace_artifact exists, with file	trace chunks removed, AlreadyArchivedError raised	Same as previous
trace_artifact exists, no file	trace_artifact destroyed, AlreadyArchivedError raised	trace_artifact destroyed, archive process runs
trace_artifact does not exist	archive process runs	Same as previous

In what scenarios does this help?

Ci::ArchiveTracesCronWorker

1. Archive fails
2. The worker will retry.
3. Ci::ArchiveTraceService will be able to remove the old archive and attempt to create a new one in the same run.

Previous behaviour:

1. Archive fails
2. The worker will retry.
3. Ci::ArchiveTraceService will remove the archive, and raise AlreadyArchivedError which the Ci::ArchiveTraceService treats as success.
4. Will not be retried until Ci::ArchiveTracesCronWorker runs again (every 17 mins)

Screenshots or Screencasts (strongly suggested)

How to setup and validate locally (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #296616 (closed)

lib/gitlab/ci/trace.rb

@@ -214,7 +214,7 @@ def unsafe_archive!
       def already_archived?
         # TODO check checksum to ensure archive completed successfully
         # See https://gitlab.com/gitlab-org/gitlab/-/issues/259619
-        trace_artifact&.archived_trace_exists?
+        trace_artifact.archived_trace_exists?
       end
 
       def unsafe_trace_conditionally_cleanup_before_retry!
@@ -223,7+223,7 @@
         if already_archived?
           # An archive already exists, so make sure to remove the trace chunks
           erase_trace_chunks!
           raise AlreadyArchivedError, 'Could not archive again'
         else
           # An archive already exists, but its associated file is not complete, so remove it
           trace_artifact.destroy!