fix: ensure API key values are converted to strings in Postman collection importer.

packages/bruno-app/src/utils/importers/postman-collection.js

@@ -422,7 +422,7 @@ const importPostmanV2CollectionItem = (brunoParent, item, parentAuth, options) =
             brunoRequestItem.request.auth.mode = 'apikey';    
             brunoRequestItem.request.auth.apikey = {
               key: authValues.key,
-              value: authValues.value,
+              value: authValues.value.toString(), // Convert the value to a string as Postman's schema does not rigidly define the type of it,
               placement: "header" //By default we are placing the apikey values in headers!
             }    
           }