If you go under Jobs and select the jobs with a Failed state, you will be able to delete them. An icon will appear to delete the failed jobs once you’ve selected 1 or more of them.
I don’t have an example in this window, but this should give you a general idea of where to go.
There is no such icon for failed jobs.
State: Failed. It’s in the same place where you see
État: Défaillant on my screenshot.