fix: ensure istio sidecar is killed if job fails

[rjferguson21]

Description

Ensure Istio sidecar is killed if Job pod exits with non-zero exit status.

Tested with Jobs (exit code zero and non-zero)

apiVersion: batch/v1
kind: Job
metadata:
  name: failing-job
  namespace: keycloak
spec:
  template:
    spec:
      containers:
      - name: fail-container
        image: quay.io/keycloak/keycloak:25.0.6 
        command: ["sh", "-c", "echo 'This will fail'; exit 1"]
      restartPolicy: Never
  backoffLimit: 3
---
apiVersion: batch/v1
kind: Job
metadata:
  name: success-job
  namespace: keycloak
spec:
  template:
    spec:
      containers:
      - name: succeed-container
        image: quay.io/keycloak/keycloak:25.0.6 
        command: ["sh", "-c", "echo 'This will succeed'; exit 0"]
      restartPolicy: Never
  backoffLimit: 3

Related Issue

Fixes #687

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Test, docs, adr added or updated as needed
• Contributor Guide followed