Helm test failure on upgrade job aborts the upgrade testing

See this job as a reference: https://repo1.dso.mil/platform-one/big-bang/bigbang/-/jobs/6935705

On this job specifically you can see it is failing at https://repo1.dso.mil/platform-one/big-bang/bigbang/-/blob/master/.gitlab-ci.yml#L164

This is the testing post clean install. While we do want to allow failures for this due to helm tests being finicky, we should have the job proceed and do the upgrade still rather than exiting immediately.