[9.x] Trim zwnbsp

[allowing]

"ZWNBSP" mean "Zero Width No-Break SPace"

The '\s' does not include it

[rodrigopedra]

Hi @allowing would you send the same change to the recently added Str::squish()?

I basically ported the same fix I used here before on PR #41877

I guess it would be nice to keep both places consistent. Unfortunately this week I won't have time to work on this.

[allowing]

@rodrigopedra :)
I may forget to reply to you, which has been implemented here. Supplement the reply for the convenience of other netizens. #41971