[VC-32659] Remove the default CPU limit

[wallrj]

In https://docs.venafi.cloud/vaas/k8s-components/c-k8s-components-best-practice/#cpu we say:

Read Stop Using CPU Limits on Kubernetes, to learn why the best practice is to set CPU requests, but not limits.

So I've removed the default CPU limit from the chart values for venafi-kubernetes-agent.

I have not changed the jetstack-agent charts, because I think it is now considered legacy.

I also removed the note about using vertical pod autoscaler, because it seems irrelevant. We don't mention VPA in the documentation or in the other charts AFAIK.

[hawksight]

Having read through I think I agree.
Ultimately the choice is down to the platform team and their policy around what to set and not set.

The bonus here is that we are less likely to have a new install in a large cluster killed for resource starvation (of CPU) and require debugging.

[maelvls]

@tfadeyi Hey, I'm not sure whether this needs to be reviewed by you, WDYT?

[maelvls]

Thanks for making this change, it's a good idea to not set CPU limits by default... especially because none of the "pros" for using CPU limits apply to the Venafi Agent: avoiding reliance on unpredictable spare cpu cycles due to low cpu requests; getting more predictable QoS; being able to charge back on multi-tenant environment.

[tfadeyi]

LGTM

I don't think it requires my approval, I think @wallrj should have permission to merge