Revert "[NI] Disable capturing/approximation type in TypeSubstitutor with enabled NI"

This reverts commit 7c4101e21c.

 #KT-31866 Fixed
 #KT-31868 Fixed
 #EA-125401 Fixed
 #KT-25290 Open

compiler/testData/diagnostics/tests/generics/varProjection/setterProjectedOutAssign.kt

@@ -7,9 +7,8 @@ interface Tr<T> {
 }
 
 fun test(t: Tr<*>) {
-    <!NI;SETTER_PROJECTED_OUT!>t.v<!> = null!!
-    <!SETTER_PROJECTED_OUT!>t.v<!> = <!NI;TYPE_MISMATCH!>""<!>
-    <!SETTER_PROJECTED_OUT!>t.v<!> = <!NI;NULL_FOR_NONNULL_TYPE!>null<!>
-
+    t.v = null!!
+    <!SETTER_PROJECTED_OUT!>t.v<!> = ""
+    <!SETTER_PROJECTED_OUT!>t.v<!> = null
     t.v checkType { _<Any?>() }
 }