[FIR] Remove the TODO from ConeTypeCompatibilityChecker

The issue is closed as fixed

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/ConeTypeCompatibilityChecker.kt

@@ -89,9 +89,6 @@ object ConeTypeCompatibilityChecker {
 
         // Next can simply focus on the type hierarchy and don't need to worry about nullability.
         val compatibilityUpperBound = when {
-            all {
-                it.isPrimitive
-            } -> Compatibility.SOFT_INCOMPATIBLE // TODO: remove after KT-46383 is fixed
             all {
                 it.isConcreteType()
             } -> Compatibility.HARD_INCOMPATIBLE