[tenant] Run cleanup job from system namespace

## What this PR does

The Helm hook that creates a job deleting all applications in a tenant
before deleting the tenant itself now runs this job from the cozy-system
namespace. This prevents conflicts with resource quotas (not enough
resources to run cleanup job) without temporary increases of the quota
or similar vulnerability-introducing hacks.

### Release note

```release-note
[tenant] Run cleanup job in system namespace to avoid conflicts on
resource quotas.
```

Signed-off-by: Timofei Larkin <lllamnyp@gmail.com>
(cherry picked from commit b94fc6c9c8)

packages/apps/tenant/templates/cleanup-job.yaml

@@ -3,7 +3,7 @@ apiVersion: v1
 kind: ServiceAccount
 metadata:
   name: {{ include "tenant.name" . }}-cleanup
-  namespace: {{ include "tenant.name" . }}
+  namespace: cozy-system
   annotations:
     helm.sh/hook: pre-delete
     helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
@@ -39,13 +39,13 @@ roleRef:
 subjects:
 - kind: ServiceAccount
   name: {{ include "tenant.name" . }}-cleanup
-  namespace: {{ include "tenant.name" . }}
+  namespace: cozy-system
 ---
 apiVersion: batch/v1
 kind: Job
 metadata:
   name: {{ include "tenant.name" . }}-cleanup
-  namespace: {{ include "tenant.name" . }}
+  namespace: cozy-system
   annotations:
     helm.sh/hook: pre-delete
     helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded