ShaneBee roasted you multiple times for no reason. Keep learning, keep developing. This skript is simple and you fixed it (sort of..)

There are 3 main things wrong with this resource.

1) Your use of local variables across 2 different events. IF you knew basic Skript, you would understand what I am talking about here and why it wouldn't work. I don't even need to run this on my server to understand this wouldn't work.

2) The indentation on the last 2 lines would clearly throw an empty section warning for line 8. Again, I don't need to even run this on my server to know the outcome.
Because of this indentation issue, a player would not be able to attack ANY entity on the server... EVER!

3) The fact that you clearly didn't run this on a server and/or even bother testing it, is what really irks me. You wrote some poorly written code, slapped it on SpigotMC and called it a day. Yet you claim in your tested minecraft versions fields that you tested on 1.17 and 1.18, which I call BS. You clearly didn't test this on anything or you'd understand it don't work.
Sure, you won't be able to attack a new join, but you won't be able to attack any entity.

The Skript community already gets enough flack for many different reasons, and people like you make this even worse.
You have written some really bad code, threw it on SpigotMC to act like you're some sort of dev, even though you couldn't have been bothered to write good/working code and/or bother to test it.

Since writing this, I decided to run it on my server to prove a point.
First things first:
""
[07:10:34 INFO]: Line 8: (test.sk)
[07:10:34 INFO]: Empty configuration section! You might want to indent one or more of the subsequent lines to make them belong to this section or remove the colon at the end of the line if you don't want this line to start a section.
[07:10:34 INFO]: Line: if {_playerProt::%victim%} is true:
""
SHOCKER... a warning about the empty section. Just as predicted.

Secondly:
I can't attack a sheep, or a cow, or ANY ENTITY on my server now.
SHOCKED AGAIN... just as predicted. All that happens is I get spammed with "This Player Has Newbie Protection", FOR... EVERY.. SINGLE... ENTITY!!!