Delete unused priority constants and ExprEventClasses registration

Author: UnderscoreTud

src/main/java/org/skriptlang/reflect/syntax/custom/CustomSyntaxModule.java

@@ -50,7 +50,6 @@ public void load(SkriptAddon addon) {
 
 			// ==Shared==
 			EffContinue::register,
-			ExprEventClasses::register,
 			ExprExpression::register,
 			ExprMatchedPattern::register,
 			ExprParseMark::register,

src/main/java/org/skriptlang/reflect/syntax/custom/shared/CustomSyntax.java

@@ -1,15 +1,9 @@
 package org.skriptlang.reflect.syntax.custom.shared;
 
 import ch.njol.skript.lang.SyntaxElement;
-import ch.njol.skript.lang.Trigger;
-import org.skriptlang.skript.registration.SyntaxInfo;
-import org.skriptlang.skript.registration.SyntaxRegistry;
-import org.skriptlang.skript.util.Priority;
 
 public interface CustomSyntax extends SyntaxElement {
 
-	Priority PRIORITY = SyntaxInfo.COMBINED, LOCAL_PRIORITY = Priority.before(PRIORITY);
-
 	CustomSyntaxInfo<? extends CustomSyntax> info();
 
 }