Remove Arbiter

Fixes #891

Author: xPaw

descriptions/AntiCheat.Arbiter.md

@@ -236,7 +236,6 @@ SCUMMVM = (?:^|/)scummvm\.exe$
 AntiCheatExpert[] = (?:^|/)AntiCheatExpert/
 AntiCheatExpert[] = (?:^|/)AceAntibotClient/
 AnyBrain = (?:^|/)anybrainSDK\.dll$
-Arbiter = (?:^|/)Arbiter\.dll$
 BattlEye = (?:^|/)BEService(?:_x64)?\.exe$
 BlackCipher[] = (?:^|/)BlackCall(?:64)?\.aes$
 BlackCipher[] = (?:^|/)BlackCat64\.sys$