chore(ci): migrate etcd, memcached, redis, and redis-cluster images to new sources

[kingsword09]

Which issue does this PR close?

Closes #6434.

Rationale for this change

Bitnami will restrict free access to most images after August 28th, 2025. This PR migrates all affected images to maintained or legacy sources to ensure future compatibility and CI stability.

What changes are included in this PR?

• Migrate etcd from bitnami/etcd to gcr.io/etcd-development/etcd
• Migrate memcached from bitnami/memcached to bitnamisecure/memcached
• Migrate redis and redis-cluster from bitnami/redis(:7.0) and bitnami/redis-cluster(:7.0) to bitnamilegacy/redis(:7.0) and bitnamilegacy/redis-cluster(:7.0)
• Update docker-compose and related configuration files accordingly

Are there any user-facing changes?

[kingsword09]

The new image ‎bitnamisecure/memcached has an issue where enabling authentication results in the error ‎saslpasswd2: command not found, causing the container to exit. This problem has already been reported bitnami/containers Issue #83591. We need to wait for this to be fixed before proceeding.

[kingsword09]

Old Image	New Image	Migration Notes
bitnami/memcached	bitnamisecure/memcached	bitnami to bitnamisecure
bitnami/etcd:latest	gcr.io/etcd-development/etcd:v3.6.4	Official image
docker.io/bitnami/redis:7.0	docker.io/bitnamilegacy/redis:7.4.3-debian-12-r0	bitnami to bitnamilegacy
docker.io/bitnami/redis-cluster:7.0	docker.io/bitnamilegacy/redis-cluster:7.4.3-debian-12-r0	bitnami to bitnamilegacy

---

@Xuanwo I’m not sure how best to resolve:

• etcd TLS migration issue:
  The official etcd image does not support the ‎ETCD_ROOT_PASSWORD environment variable, so we are using ‎docker.io/bitnamilegacy/etcd:3.6.4-debian-12-r0 instead.
• Memcached authentication issue:
  When enabling authentication with the new memcached image, the error ‎saslpasswd2: command not found occurs, so we switched to ‎docker.io/bitnamilegacy/memcached:1.6.39-debian-12-r0.
• Legacy image maintenance:
  Images from ‎bitnamilegacy will not receive future updates, which may affect long-term maintenance and security, since there seem to be very few actively maintained alternatives available for etcd and memcached..

I’m not sure how to address these problems and would appreciate your suggestions or guidance on possible solutions.

[Xuanwo]

bitnamilegacy looks good to me so far. Can you create an issue to upstream about the authentication and tls issues? I think this PR itself is good to go.

[Xuanwo]

Thank you for working on this, really appreciated!

[kingsword09]

bitnamilegacy looks good to me so far. Can you create an issue to upstream about the authentication and tls issues? I think this PR itself is good to go.

memcached issue: bitnami/containers#83591
etcd discussions: etcd-io/etcd#20601

Waiting for upstream fixes.