feat(logical-backup): add configurable job history limits and TTL

Adds three new configuration options for logical backup cronjobs:
- logical_backup_successful_jobs_history_limit (default: 3)
- logical_backup_failed_jobs_history_limit (default: 3)
- logical_backup_ttl_seconds_after_finished (default: 86400)

These options control how many completed/failed backup jobs are
retained by Kubernetes and when finished jobs are automatically
deleted. This prevents accumulation of old backup jobs and pods
in namespaces with many PostgreSQL clusters.

Also updates the CronJob comparison logic to detect changes in
these new fields and trigger reconciliation when needed.

Closes zalando/postgres-operator#1092

charts/postgres-operator/crds/operatorconfigurations.yaml

@@ -561,6 +561,18 @@ spec:
                     default: "30 00 * * *"
                   logical_backup_cronjob_environment_secret:
                     type: string
+                  logical_backup_failed_jobs_history_limit:
+                    type: integer
+                    minimum: 0
+                    default: 3
+                  logical_backup_successful_jobs_history_limit:
+                    type: integer
+                    minimum: 0
+                    default: 3
+                  logical_backup_ttl_seconds_after_finished:
+                    type: integer
+                    minimum: 0
+                    default: 86400
               debug:
                 type: object
                 properties:

charts/postgres-operator/values.yaml

@@ -402,6 +402,12 @@ configLogicalBackup:
   logical_backup_schedule: "30 00 * * *"
   # secret to be used as reference for env variables in cronjob
   logical_backup_cronjob_environment_secret: ""
+  # number of successful backup jobs to keep in cronjob history
+  logical_backup_successful_jobs_history_limit: 3
+  # number of failed backup jobs to keep in cronjob history
+  logical_backup_failed_jobs_history_limit: 3
+  # TTL in seconds after which finished backup jobs are automatically deleted
+  logical_backup_ttl_seconds_after_finished: 86400
 
 # automate creation of human users with teams API service
 configTeamsApi: