No alerts on canary non analysis phase failures

[macox]

Describe the bug

During a canary deployment there are a number of situations where any configured alerts are not fired when the canary fails:

• pre-rollout webhook
• exceeded its progress deadline when (canary/primary) pods not ready

To Reproduce

Configure a canary deployment with suitable alert provider e.g. Slack. Include a pre-rollout webhook that purposely fail.
Despite the canary resulting on a failed state no alert is sent and the end user has no visible of what has happened to their canary deployment

Expected behavior

Alert on:

• pre-rollout webhook failing
• exceeded its progress deadline when (canary/primary) pods not ready

Allow these alerts to be muted if required

Additional context

• Flagger version: v1.37.0
• Kubernetes version: v1.26
• Service Mesh provider: Istio
• Ingress provider: Istio