Use go 1.19's soft memory limit when it is released

[enj]

golang/go#48409 is expected to release in go 1.19 and will allow us to do something like deployment.spec.template.spec.containers[0] for the supervisor, concierge and kube-cert-agent deployments:

      env:
       # reduce OOM likelyhood
       - name: GOMEMLIMIT
          valueFrom:
            resourceFieldRef:
              containerName: #@ defaultResourceName()
              resource: limits.memory

[joshuatcasey]

Here's a helpful example: https://www.ardanlabs.com/blog/2024/02/kubernetes-memory-limits-go.html

[joshuatcasey]

Note that containerName is optional for environment variables: https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.30/#resourcefieldselector-v1-core

[joshuatcasey]

I've pushed this to a branch jtc/use-soft-memory-limit-1103 but will hold off on a PR temporarily as we've got other PRs using up the pipeline.