fix(signals): skip assertions when ngDevMode is not defined (#4703)

Closes #4699

Author: markostanimirovic

modules/signals/entities/src/helpers.ts

@@ -201,7 +201,11 @@ export function updateEntitiesMutably(
     didMutate = DidMutate.Both;
   }
 
-  if (ngDevMode && state.ids.length !== Object.keys(state.entityMap).length) {
+  if (
+    typeof ngDevMode !== 'undefined' &&
+    ngDevMode &&
+    state.ids.length !== Object.keys(state.entityMap).length
+  ) {
     console.warn(
       '@ngrx/signals/entities: Entities with IDs:',
       ids,

modules/signals/src/signal-store-assertions.ts

@@ -6,7 +6,7 @@ export function assertUniqueStoreMembers(
   store: InnerSignalStore,
   newMemberKeys: Array<string | symbol>
 ): void {
-  if (!ngDevMode) {
+  if (typeof ngDevMode === 'undefined' || !ngDevMode) {
     return;
   }