Plan to release v3.4.42

[ivanvc]

What would you like to be added?

The etcd patch release criteria has been met for our release-3.4 stable branch, so we should release v3.4.42.

Work in progress CHANGELOG is: https://github.com/etcd-io/etcd/blob/main/CHANGELOG/CHANGELOG-3.4.md#v3442-tbc

The list of commits included since the previous release is: v3.4.41...release-3.4:

• [release-3.4] Fix race between read index and leader change #21385
• [release-3.4] bump Go to 1.25.7 #21406
• [release-3.4] Don't reuse same ReadIndex #21423
• [release-3.4] Bump golang.org/x/net@ v0.51.0 fixes GO-2026-4559 #21444
• [release-3.4] Bump Go to 1.25.8 #21461
• [release-3.4] dependency: Bump google.golang.org/grpc from v1.58.3 to 1.79.3 #21502

Outstanding tasks before releasing this version:

• Bump golang.org/x/net to v0.51.0 to resolve GO-2026-4559 #21392

Release team

GitHub handle	Role
@ivanvc	Release Lead

Why is this needed?

Regular patch releases are vital to ensure our users have bug-free and secure software.