fix(angular): warn in ng-packagr executors when finding conflicting p…

…ackage export conditions

packages/angular/src/executors/ng-packagr-lite/ng-packagr-adjustments/ng-package/entry-point/write-package.transform.ts

@@ -397,20 +397,15 @@ function generatePackageExports(
     subpath: string,
     mapping: ConditionalExport
   ) => {
-    if (exports[subpath] === undefined) {
-      exports[subpath] = {};
-    }
-
+    exports[subpath] ??= {};
     const subpathExport = exports[subpath];
 
     // Go through all conditions that should be inserted. If the condition is already
     // manually set of the subpath export, we throw an error. In general, we allow for
     // additional conditions to be set. These will always precede the generated ones.
-    for (const conditionName of Object.keys(mapping) as [
-      keyof ConditionalExport
-    ]) {
+    for (const conditionName of Object.keys(mapping)) {
       if (subpathExport[conditionName] !== undefined) {
-        throw Error(
+        logger.warn(
           `Found a conflicting export condition for "${subpath}". The "${conditionName}" ` +
             `condition would be overridden by ng-packagr. Please unset it.`
         );