Remove assert that does not hold for light classes on erroneous code

When clashing overloads are declared in the code, it's better to still be able to build light classes

compiler/backend-common/src/bridges/impl.kt

@@ -78,7 +78,6 @@ public fun findTraitImplementation(descriptor: CallableMemberDescriptor): Callab
     var implementation: CallableMemberDescriptor? = null
     for (overriddenDeclaration in filteredOverriddenDeclarations) {
         if (DescriptorUtils.isTrait(overriddenDeclaration.getContainingDeclaration()) && overriddenDeclaration.getModality() != Modality.ABSTRACT) {
-            assert(implementation == null) { "Ambiguous overridden declaration: $descriptor" }
             implementation = overriddenDeclaration
         }
     }