Remove maven threads configuration based on GOMAXPROCS

[lburgazzoli]

What happened?

The maven_command sets mavne's artifact and execution threads to the value of GOMAXPROCS however, The Go runtime doesn’t know it’s running in k8s hence, GOMAXPROCS reports the number of cores on the node:

camel-k/pkg/util/maven/maven_command.go

Lines 92 to 98 in 37fb704

	if !util.StringContainsPrefix(c.context.AdditionalArguments, "-Dmaven.artifact.threads") {
	args = append(args, "-Dmaven.artifact.threads="+strconv.Itoa(runtime.GOMAXPROCS(0)))
	}
	if !util.StringSliceExists(c.context.AdditionalArguments, "-T") {
	args = append(args, "-T", strconv.Itoa(runtime.GOMAXPROCS(0)))
	}

This seems to be wrong an could potential lead to misbehavior as maven is configured to use more resources than what is actually available for the Pod.

Steps to reproduce

1. start minikube with i.e. half of the cores available
2. observe an integration build logs
3. you should see that the maven's -T flag has a value greater than the number of the configured cores