update changelog and api spec

CHANGELOG.md

@@ -7,10 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [8.1.0]
 
 ### Changed
-- The `processing_times` field of a job's API response now has a value of `null` if the job failed or if there was a failure to calculate processing times.
+- A job's `processing_times` field is now set to `null` rather than `[]` if there was an error while calculating processing times. As before, an error while calculating processing times causes the job to fail.
+- There is no longer any attempt to calculate `processing_times` for failed jobs. All failed jobs now have a `processing_times` value of `null`.
+- The processing time value for each processing step must now be greater than zero. (Previously, a value of zero indicated that the processing step had no AWS Batch attempts.)
 
 ### Fixed
-- Resolves a regression introduced by the previous release (v8.0.0) in which some jobs reported negative processing times if the underlying AWS Batch jobs had a failed attempt that did not include a `StartedAt` field. Fixes <https://github.com/ASFHyP3/hyp3/issues/2485>
+- Resolves a regression introduced by the previous release (v8.0.0) in which a processing step could report a negative processing time if the underlying AWS Batch job had a failed attempt that did not include a `StartedAt` field. Fixes <https://github.com/ASFHyP3/hyp3/issues/2485>
 - Upgrade from `flask==2.2.5` to `Flask==3.0.3`. Fixes a bug in which Dependabot was not tracking Flask upgrades because we specified the dependency name as lowercase.
 - Specify our custom JSON encoder by subclassing `flask.json.provider.JSONProvider`. See <https://github.com/pallets/flask/pull/4692>
 

apps/api/src/hyp3_api/api-spec/openapi-spec.yml.j2

@@ -409,7 +409,7 @@ components:
     processing_times:
       description: >
         List of run times for the job's processing steps in the order that they were executed.
-        A null value indicates that the job failed or there was an error while calculating processing times.
+        A null value indicates that the job failed.
       type: array
       nullable: true
       items: