feat(helm): add configurable job history limits for heartbeat cronjob

Problem

The heartbeat CronJob had successfulJobsHistoryLimit hardcoded to 0 and
failedJobsHistoryLimit was not set at all. This prevented users from
retaining job history for debugging and monitoring purposes.

Solution

Add successfulJobsHistoryLimit and failedJobsHistoryLimit as configurable
values under the heartbeat section in values.yaml. The template now uses
these values with sensible defaults (0 for successful, 1 for failed).

Validation

- Verified the Helm template renders correctly with default values
- Verified custom values can be passed via --set heartbeat.successfulJobsHistoryLimit=X

Signed-off-by: mfeix <marcel.feix@exxcellent.de>

Author: Syndlex

charts/linkerd-control-plane/templates/heartbeat.yaml

@@ -24,7 +24,8 @@ spec:
   {{ else -}}
   schedule: "{{ dateInZone "04 15 * * *" (now | mustDateModify "+10m") "UTC"}}"
   {{ end -}}
-  successfulJobsHistoryLimit: 0
+  successfulJobsHistoryLimit: {{ .Values.heartbeat.successfulJobsHistoryLimit | default 0 }}
+  failedJobsHistoryLimit: {{ .Values.heartbeat.failedJobsHistoryLimit | default 1 }}
   jobTemplate:
     spec:
       template:

charts/linkerd-control-plane/values.yaml

@@ -509,6 +509,11 @@ identity:
 disableHeartBeat: false
 # -- Config for the heartbeat cronjob
 # heartbeatSchedule: "0 0 * * *"
+heartbeat:
+  # -- Number of successful job runs to retain
+  successfulJobsHistoryLimit: 0
+  # -- Number of failed job runs to retain
+  failedJobsHistoryLimit: 1
 
 # proxy injector configuration
 proxyInjector: