[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/fir/resolve/tests/org/jetbrains/kotlin/fir/FirOldFrontendDiagnosticsTestGenerated.java

@@ -10371,6 +10371,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
                 runTest("compiler/testData/diagnostics/tests/inference/coercionToUnit/coercionWithoutExpectedType.kt");
             }
 
+            @TestMetadata("coersionWithAnonymousFunctionsAndUnresolved.kt")
+            public void testCoersionWithAnonymousFunctionsAndUnresolved() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inference/coercionToUnit/coersionWithAnonymousFunctionsAndUnresolved.kt");
+            }
+
             @TestMetadata("indirectCoercionWithExpectedType.kt")
             public void testIndirectCoercionWithExpectedType() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/inference/coercionToUnit/indirectCoercionWithExpectedType.kt");