Build our own otel collector binary in CI

[MichaelThamm]

Issue

We need to build our own otelcol binary

• Add functionality to update the $VERSION from upstream contrib to additions.yaml
• Update the contributing prerequisite steps:

sudo snap install microk8s
sudo snap install kubectl --classic
microk8s config | tee ~/.kube/config

• Maybe we can use the upstream otelcol binary release and then just add our custom elements on top (delta).
• Add some form of diff check between upstream and ours to check if a new one was added upstream?

[MichaelThamm]

@lucabello

just test-integration 0.120.0 passes (just test-integration) but <= 0.119.0 names the job otel-collector (in the goss.yaml) rather than otelcol. Since there is 1 goss.yaml, how do we handle this for variations per rock version?

We also have a hardcoded config.yaml file now, but will we care if upstream removes or adds to the config? Will we follow accordingly or just roll our own from now on?

[lucabello]

I pushed some changes, moving the ocb manifest generation in the justfile just ocb-manifest and calling that when pulling a new rock update.