Update developer guide to handle missing training-operator-webhook-cert

[franciscojavierarceo]

When running make run based on the developer guide I end up with a cert error:

2024-04-17T16:25:16-04:00       ERROR   setup   problem running manager {"error": "acquiring secret to update certificates: Secret \"training-operator-webhook-cert\" not found", "errorVerbose": "Secret \"training-operator-webhook-cert\" not found\nacquiring secret to update certificates\ngithub.com/open-policy-agent/cert-controller/pkg/rotator.(*CertRotator).refreshCertIfNeeded.func1\n\t/Users/farceo/go/pkg/mod/github.com/open-policy-agent/cert-controller@v0.10.1/pkg/rotator/rotator.go:317\nk8s.io/apimachinery/pkg/util/wait.runConditionWithCrashProtection\n\t/Users/farceo/go/pkg/mod/k8s.io/apimachinery@v0.29.3/pkg/util/wait/wait.go:145\nk8s.io/apimachinery/pkg/util/wait.ExponentialBackoff\n\t/Users/farceo/go/pkg/mod/k8s.io/apimachinery@v0.29.3/pkg/util/wait/backoff.go:461\ngithub.com/open-policy-agent/cert-controller/pkg/rotator.(*CertRotator).refreshCertIfNeeded\n\t/Users/farceo/go/pkg/mod/github.com/open-policy-agent/cert-controller@v0.10.1/pkg/rotator/rotator.go:350\ngithub.com/open-policy-agent/cert-controller/pkg/rotator.(*CertRotator).Start\n\t/Users/farceo/go/pkg/mod/github.com/open-policy-agent/cert-controller@v0.10.1/pkg/rotator/rotator.go:278\nsigs.k8s.io/controller-runtime/pkg/manager.(*runnableGroup).reconcile.func1\n\t/Users/farceo/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.17.2/pkg/manager/runnable_group.go:223\nruntime.goexit\n\t/opt/homebrew/Cellar/go/1.22.2/libexec/src/runtime/asm_arm64.s:1222"}

I'm not sure if I need to create a cert locally or something but that didn't seem like the obvious next step. My guess is that the #2035 unintentionally impacted local development.

[ALPHA-1503]

Hello :),
I'm facing the same issue did you fix it?

Thanks,
Arnaud.

[franciscojavierarceo]

#2074