[NI] Soften restictions on using Nothing as proper constraint for full call completion

Consider lower `Nothing` constraint non-proper only if there is a dependant not analyzed postponed atom.
Early completion to `Nothing` provides data flow info for smart casts.

KT-35668 Fixed

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

@@ -10582,6 +10582,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
                 runTest("compiler/testData/diagnostics/tests/inference/completion/kt33166.kt");
             }
 
+            @TestMetadata("lambdaWithVariableAndNothing.kt")
+            public void testLambdaWithVariableAndNothing() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inference/completion/lambdaWithVariableAndNothing.kt");
+            }
+
             @TestMetadata("partialForIlt.kt")
             public void testPartialForIlt() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/inference/completion/partialForIlt.kt");
@@ -17846,6 +17851,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
             runTest("compiler/testData/diagnostics/tests/regressions/kt3535.kt");
         }
 
+        @TestMetadata("kt35668.kt")
+        public void testKt35668() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/regressions/kt35668.kt");
+        }
+
         @TestMetadata("kt3647.kt")
         public void testKt3647() throws Exception {
             runTest("compiler/testData/diagnostics/tests/regressions/kt3647.kt");