Bump coreos/etcd from v3.5.21 to v3.6.7

Bumps coreos/etcd from v3.5.21 to v3.6.7.

---
updated-dependencies:
- dependency-name: coreos/etcd
  dependency-version: v3.6.7
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

dev.Dockerfile

@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 FROM registry.k8s.io/kube-apiserver:v1.33.2 AS kube-apiserver
-FROM quay.io/coreos/etcd:v3.5.21 AS etcd
+FROM quay.io/coreos/etcd:v3.6.7 AS etcd
 FROM golang:1.25.4 AS tools
 
 COPY --from=kube-apiserver /usr/local/bin/kube-apiserver /testbin/kube-apiserver