scale: eval creation on scaling assuming service job type

[jrasell]

Tested on main, locally on M2 MacOS.

When scaling a job, the resulting evaluation is always created with Type = "Service" regardless of the type parameter within the jobspec that is being scaled. This can result in jobs of type batch being scaled and the created evaluation detailing type service.

JobSpec:

job "example" {
  datacenters = ["dc1"]
  type        = "batch"

  group "cache" {
    count = 2
    network {
      port "db" {
        to = 6379
      }
    }
    task "redis" {
      driver = "docker"
      config {
        image = "redis:7"
        ports = ["db"]
      }
    }
  }
}

When scaling the above job via nomad job scale example 10 the following evaluation is created.

ID                 = 97bc2abd
Create Time        = 31s ago
Modify Time        = 31s ago
Status             = complete
Status Description = complete
Type               = service
TriggeredBy        = job-scaling
Job ID             = example
Namespace          = default
Priority           = 50
Placement Failures = false