fix(myorg-assistant): point cronjobs at registry image + add imagePullSecrets

CronJob pods were stuck in ImagePullBackOff because they referenced
the local-only image 'myorg-assistant:latest' which is not present
on the node. Switch all 5 cronjobs to the Gitea registry image
git.rogi.casa/roger/myorg-assistant/myorg-assistant:fcf79bf
(matching the Deployment), set imagePullPolicy: Always, and add
imagePullSecrets: gitea-registry so they can authenticate to the
private registry.

myorg-assistant/cronjobs/deadline-checker.yaml

@@ -22,10 +22,12 @@ spec:
             job: deadline-checker
         spec:
           restartPolicy: OnFailure
+          imagePullSecrets:
+          - name: gitea-registry
           containers:
           - name: deadline-checker
-            image: myorg-assistant:latest
-            imagePullPolicy: IfNotPresent
+            image: git.rogi.casa/roger/myorg-assistant/myorg-assistant:fcf79bf
+            imagePullPolicy: Always
             command:
             - python
             - run_job.py