refactor(migrations): fix batch test of signal input migration failing (angular#57961)

The batch test was failing (it doesn't run on CI for resource reasons)
because incompatibilities were not properly "incorporated" in batch
execution mode (due to enum values of 0 being incorrectly checked via
truthy).

This is only visible in batch scenarios in two cases:

 - when a class was manually instantiated, between targets
 - when a class was overridden by a derived class, between targets

PR Close angular#57961

Author: devversion

packages/core/schematics/migrations/signal-migration/src/batch/populate_global_data.ts

@@ -24,14 +24,14 @@ export function populateKnownInputsFromGlobalData(
     }
 
     const inputMetadata = knownInputs.get({key})!;
-    if (info.memberIncompatibility) {
+    if (info.memberIncompatibility !== null) {
       knownInputs.markFieldIncompatible(inputMetadata.descriptor, {
         context: null, // No context serializable.
         reason: info.memberIncompatibility,
       });
     }
 
-    if (info.owningClassIncompatibility) {
+    if (info.owningClassIncompatibility !== null) {
       knownInputs.markClassIncompatible(
         inputMetadata.container.clazz,
         info.owningClassIncompatibility,