==================
WARNING: DATA RACE
Read at 0x00c0001db420 by goroutine 22:
  github.com/redis/go-redis/v9.(*Options).clone()
      /Users/ruben/work/go-redis/options.go:423 +0xf4
  github.com/redis/go-redis/v9.TestOptionsCloneMaintNotificationsRace.func2()
      /Users/ruben/work/go-redis/options_test.go:433 +0x9c

Previous write at 0x00c0001db420 by goroutine 21:
  github.com/redis/go-redis/v9.TestOptionsCloneMaintNotificationsRace.func1()
      /Users/ruben/work/go-redis/options_test.go:423 +0x160```
      
in various places `optLock` is already used to guard against this, except when doing `opt.clone()`, so wrapping that as well should fix the issue 

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Touches core client option cloning used in transactions/timeouts by adding locking; low functional change but could affect concurrency/performance or introduce lock contention if misused.
> 
> **Overview**
> Fixes a detected data race between `initConn` mutating `MaintNotificationsConfig.Mode` and concurrent `Options.clone()` calls by introducing `baseClient.cloneOpt()` that clones options under `optLock`.
> 
> Updates `withTimeout` and `Client.newTx()` to use the new locked clone path, and adds a `-race` regression test that concurrently toggles maintnotifications mode while cloning options.
> 
> <sup>Written by [Cursor Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit 384c4f66107c2bf0c4c509ea1866c26c3394a61c. This will update automatically on new commits. Configure [here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->