[FIR] Fix nullability of types produced by ConeRawScopeSubstitutor

#KT-66067 Fixed

compiler/testData/codegen/box/javaInterop/kjkWithRawTypes.kt

@@ -0,0 +1,28 @@
+// TARGET_BACKEND: JVM_IR
+// ISSUE: KT-66067
+// FILE: Java1.java
+public class Java1<T extends Number> {
+    public int foo(T t) {
+        return 1;
+    }
+}
+
+// FILE: Java2.java
+public class Java2 extends KotlinClass {
+    public int foo(Object t) {
+        return 2;
+    }
+}
+
+// FILE: 1.kt
+class A : Java2()   // Kotlin ← Java ← Kotlin ← Java
+
+open class KotlinClass<T> : Java1<T>() where T: Number
+
+fun box(): String {
+    if (A().foo(null) != 1) return "FAIL 1";
+    if (A().foo(null as Number?) != 1) return "FAIL 1";
+    if (A().foo("") != 2) return "FAIL 1";
+
+    return "OK"
+}