[NI] Discriminate Nothing? result type from nullability constraints

Nullability constraints should not be chosen when proper
argument constraints for variables in contravariant position present.

^KT-32106 Fixed
^KT-33166 Fixed

compiler/testData/diagnostics/tests/inference/nestedCalls/preferNothingToBound.txt

@@ -0,0 +1,4 @@
+package
+
+public val v: kotlin.Nothing?
+public fun </*0*/ K> id(/*0*/ arg: K): K