[NI] Remove lambda coersion to Unit in case of error return type(s)

Coersion to Unit from error type leads to misleading type mismatches:
"expected <expected lambda return type> found Unit", despite no user-provided Unit / empty lambda.
These diagnostics were collected, but not reported before, and that had been disguising the issue for a while.

KT-34729 Fixed

compiler/testData/diagnostics/testsWithStdLib/resolve/hidesMembers.fir.kt

@@ -1,5 +1,6 @@
 // !CHECK_TYPE
 // !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !WITH_NEW_INFERENCE
 
 // FILE: 2.kt
 package b

compiler/testData/diagnostics/testsWithStdLib/resolve/hidesMembers.kt

@@ -1,5 +1,6 @@
 // !CHECK_TYPE
 // !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !WITH_NEW_INFERENCE
 
 // FILE: 2.kt
 package b
@@ -41,7 +42,7 @@ fun test(a: A) {
 
     a.<!OVERLOAD_RESOLUTION_AMBIGUITY!>forEach<!>("")
 
-    with(a) {
+    <!NI;NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>with<!>(a) {
         forEach() checkType { _<String>() }
 
         forEach(1) checkType { _<Int>() }

compiler/testData/diagnostics/testsWithStdLib/resolve/hidesMembers2.fir.kt

@@ -1,5 +1,7 @@
 // !CHECK_TYPE
 // !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !WITH_NEW_INFERENCE
+
 class A {
     fun forEach() = this
     fun forEach(i: Int) = this

compiler/testData/diagnostics/testsWithStdLib/resolve/hidesMembers2.kt

@@ -1,5 +1,7 @@
 // !CHECK_TYPE
 // !DIAGNOSTICS: -UNUSED_EXPRESSION -UNUSED_PARAMETER -UNUSED_VARIABLE
+// !WITH_NEW_INFERENCE
+
 class A {
     fun forEach() = this
     fun forEach(i: Int) = this
@@ -35,7 +37,7 @@ fun test2(a: A) {
     a.forEach() checkType { _<String>() }
     a.<!OVERLOAD_RESOLUTION_AMBIGUITY!>forEach<!>(1)
 
-    with(a) {
+    <!NI;NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>with<!>(a) {
         forEach() checkType { _<String>() }
         <!OVERLOAD_RESOLUTION_AMBIGUITY!>forEach<!>(1)
     }