storage: fix bug for the testrace of TestSystemZoneConfigs

[a6802739]

Fixes #19180.
Fixes #19207.

@a-robinson. PLAT.

I have run make testrace for this test about 10 times, and it seems ok.

The main problem I think is when we try to update desc.Replicas = append(desc.Replicas, newReplica), it will race with other goroutines, so I make a copy for rangeInfo.Desc.Replicas.

[cockroach-teamcity]

This change is 

[tbg]

Ah, hadn't seen this -- I just independently opened a PR with a fix: https://github.com/cockroachdb/cockroach/pull/19212/files

Mind using the code from my PR (since I think it's a little cleaner) and add Fixes #19207. to your commit message, and then we can merge this and I close mine?

BTW, I think the Fixes XYZ must be on its own line, so like this:

Fixes #19207.
Fixes #19180.

[a6802739]

@tschottdorf, Thank you very much.

Yes, I have seen your code, It's definitely much cleaner.

And Thanks for your kind remind about Fixes, I have changed it, It looks much better now. :)

[tbg]

Looks good! Merge whenever you're ready.

[a-robinson]

LGTM, thanks @a6802739!

Looks good! Merge whenever you're ready.

Did you just LGTM your own code? 🤔