Rename annotations package to annotation

The rest of our package names are singular.

deob-annotations/src/main/java/dev/openrs2/deob/annotation/OriginalName.java

@@ -1,4 +1,4 @@
-package dev.openrs2.deob.annotations;
+package dev.openrs2.deob.annotation;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Target;

deob/src/main/java/dev/openrs2/deob/transform/OriginalNameTransformer.java

@@ -4,7 +4,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import dev.openrs2.asm.Transformer;
-import dev.openrs2.deob.annotations.OriginalName;
+import dev.openrs2.deob.annotation.OriginalName;
 import org.objectweb.asm.Type;
 import org.objectweb.asm.commons.Remapper;
 import org.objectweb.asm.tree.AnnotationNode;