Merge branch 'drosse/incomplete-traces-handling' into 'master'

Improve support for incomplete traces

Closes gitlab-org/opstrace/opstrace#2692

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/146803



Merged-by: Jose Ivan Vargas <jvargas@gitlab.com>
Approved-by: Jose Ivan Vargas <jvargas@gitlab.com>
Reviewed-by: Daniele Rossetti <drossetti@gitlab.com>
Reviewed-by: Marina Mosti <mmosti@gitlab.com>
Co-authored-by: Daniele Rossetti <drossetti@gitlab.com>