Revert "[FIR] Let attributes opt-in to participating in ConeClassLikeTypeImpl structural equality"

This reverts commit 9189154cae.

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/EnhancedTypeForWarningAttribute.kt

@@ -25,25 +25,6 @@ class EnhancedTypeForWarningAttribute(
 
     override val keepInInferredDeclarationType: Boolean
         get() = true
-
-    override val implementsEquality: Boolean
-        get() = true
-
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (javaClass != other?.javaClass) return false
-
-        other as EnhancedTypeForWarningAttribute
-
-        if (coneType != other.coneType) return false
-
-        return true
-    }
-
-    override fun hashCode(): Int {
-        var result = coneType.hashCode()
-        return result
-    }
 }
 
 val ConeAttributes.enhancedTypeForWarning: EnhancedTypeForWarningAttribute? by ConeAttributes.attributeAccessor<EnhancedTypeForWarningAttribute>()