`JobRun` not being saved with the fully qualified fuzz_target name.

[oliverchang]

It looks like our JobRun stats are not being uploaded with the fully qualified fuzzer name (e.g. "libFuzzer_project_target"), and instead just being uploaded with the parent name ("libFuzzer").

This is leading to some 404s with queries on our fuzzer stats page for the exact fuzz target name.

Possibly caused by #4137.