Fix build timing script and image versions

[jjnesbitt]

There are a couple of things that are causing the analytics DB to not contain the added fields from #635

1. I forgot to add the @contextmanager decorator to the get_job_artifacts_file function. The lack of this decorator should have caused sentry errors that would point to the issue. However, that didn't happen because...
2. Due to the fallout of Add new fields to analytics database #635 regarding version collision, the hastily made follow-up PR Bump versions for build timing pods #690 didn't actually bump the version of upload-build-timings that was used in the build timing webhook. So events that were being sent to the webhook were still using the old version of the script, and not adding in those fields.

[mvandenburgh]

Do you need to bump this image version as well? https://github.com/spack/spack-infrastructure/blob/fix-upload-build-timing/k8s/production/custom/build-timing-processor/deployments.yaml#L26

[jjnesbitt]

Do you need to bump this image version as well? fix-upload-build-timing/k8s/production/custom/build-timing-processor/deployments.yaml#L26

Yes, good catch