Don't use preemptible VMs for presubmit + other fixes

[DanG100]

• Using not preemptible should help reduce flakiness
• The local test is unstable to github actions so run it on cloudbuild
• I'm not that make load was working as expected

[github-actions]

Pull Request Test Coverage Report for Build 5872907818

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 306 unchanged lines in 9 files lost coverage.
• Overall coverage remained the same at 2.499%

---

Files with Coverage Reduction	New Missed Lines	%
gnmi/oc/networkinstance/networkinstance-0.go	3	0.27%
dataplane/internal/kernel/kerneltest/kernel.go	10	72.6%
dataplane/server.go	11	0%
dataplane/internal/kernel/kernel.go	22	0%
dataplane/forwarding/fwdport/ports/kernel.go	25	7.62%
dataplane/forwarding/fwdport/ports/tap.go	32	1.8%
lemming.go	46	70.64%
dataplane/handlers/interface.go	62	0%
dataplane/internal/engine/engine.go	95	0%

Totals
Change from base Build 5869943441:	0.0%
Covered Lines:	13212
Relevant Lines:	528743

---

💛 - Coveralls

[wenovus]

I think local_tests still counts as a medium since it runs for a few minutes right now. I also think this should be run as part of GitHub Actions rather than on cloudbuild. Perhaps add another workflow job that runs the medium jobs?

[DanG100]

the local test has been flaky on the github action runner, i want to see if solves the issue https://github.com/openconfig/lemming/actions/runs/5860193044/job/15887753577
https://github.com/openconfig/lemming/actions/runs/5686228980/job/15412660877

[wenovus]

Ok LGTM