CODER_PROC_PRIO_MGMT puts noise in logs when processes exit before renicing #14651
Description
CODER_PROC_PRIO_MGMT seems to have a race when processes exit before the agent has a chance to renice it. This leads to a lot of noise in workspace logs:
2024-09-11 22:28:12.826 [warn] unable to get proc niceness cmd="" pid=7899 ...
2024-09-11 22:28:12.827 [info] error= get priority for "":
2024-09-11 22:28:12.827 [info] github.com/coder/coder/v2/agent/agentproc.(*Process).Niceness
2024-09-11 22:28:12.827 [info] /go/pkg/mod/github.com/coder/coder/v2@v2.14.3/agent/agentproc/proc_unix.go:107
2024-09-11 22:28:12.827 [info] - get priority:
2024-09-11 22:28:12.827 [info] github.com/coder/coder/v2/agent/agentproc.UnixSyscaller.GetPriority
2024-09-11 22:28:12.827 [info] /go/pkg/mod/github.com/coder/coder/v2@v2.14.3/agent/agentproc/syscaller_unix.go:30
2024-09-11 22:28:12.827 [info] - no such process