fix etcd topologySpreadConstraints (#1331)

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## What this PR does


### Release note

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```release-note
- fix etcd topologySpreadConstraints
```

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* New Features
* Added optional cluster-level configuration to override topology spread
constraints for etcd pods, enabling custom scheduling rules. Defaults
remain unchanged when not configured.

* Chores
  * Bumped etcd chart version to 2.9.1 for release tracking.
* Updated versions mapping to include 2.9.1 and pinned the previous
2.9.0 entry to a specific commit for reproducibility.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/extra/etcd/Chart.yaml

@@ -3,4 +3,4 @@ name: etcd
 description: Storage for Kubernetes clusters
 icon: /logos/etcd.svg
 type: application
-version: 2.9.0
+version: 2.9.1

packages/extra/etcd/templates/etcd-cluster.yaml

@@ -49,6 +49,14 @@ spec:
         {{- with .Values.resources }}
         resources: {{- include "cozy-lib.resources.sanitize" (list . $) | nindent 10 }}
         {{- end }}
+    {{- $configMap := lookup "v1" "ConfigMap" "cozy-system" "cozystack-scheduling" }}
+    {{- $rawConstraints := "" }}
+    {{- if $configMap }}
+      {{- $rawConstraints = get $configMap.data "globalAppTopologySpreadConstraints" }}
+    {{- end }}
+    {{- if $rawConstraints }}
+      {{- $rawConstraints | fromYaml | toYaml | nindent 6 }}
+    {{- else }}
       topologySpreadConstraints:
       - maxSkew: 1
         topologyKey: "kubernetes.io/hostname"
@@ -56,6 +64,7 @@ spec:
         labelSelector:
           matchLabels:
             app.kubernetes.io/instance: etcd
+    {{- end }}
   podDisruptionBudgetTemplate: {}
 ---
 apiVersion: cert-manager.io/v1

packages/extra/versions_map

@@ -13,7 +13,8 @@ etcd 2.6.0 8c460528
 etcd 2.6.1 45a7416c
 etcd 2.7.0 632224a3
 etcd 2.8.0 4369b031
-etcd 2.9.0 HEAD
+etcd 2.9.0 8ddbe32e
+etcd 2.9.1 HEAD
 info 1.0.0 93bdf411
 info 1.0.1 632224a3
 info 1.1.0 HEAD