frontend-test-utils: marking as breaking

Signed-off-by: Vincenzo Scamporlino <vincenzos@spotify.com>

.changeset/real-seals-dress.md

@@ -1,5 +1,5 @@
 ---
-'@backstage/frontend-test-utils': patch
+'@backstage/frontend-test-utils': minor
 ---
 
-Add a new utility `renderTestApp` to `@backstage/frontend-test-utils` that simplifies rendering extensions within the Backstage application context for testing purposes. This utility replaces the use of `renderInTestApp` when the `extensions` option is needed.
+**BREAKING**: Removed the `extensions` option from `renderInTestApp`. If you need to pass extensions to the test app, use the new `renderTestApp` utility instead.

packages/frontend-test-utils/report.api.md

@@ -145,7 +145,6 @@ export type TestAppOptions = {
     [path: string]: RouteRef;
   };
   config?: JsonObject;
-  extensions?: ExtensionDefinition<any>[];
   features?: FrontendFeature[];
   initialRouteEntries?: string[];
 };

packages/frontend-test-utils/src/app/renderInTestApp.tsx

@@ -67,13 +67,6 @@ export type TestAppOptions = {
    */
   config?: JsonObject;
 
-  /**
-   * Additional extensions to add to the test app.
-   *
-   * @deprecated Use `renderTestApp` instead.
-   */
-  extensions?: ExtensionDefinition<any>[];
-
   /**
    * Additional features to add to the test app.
    */
@@ -195,10 +188,6 @@ export function renderInTestApp(
     }
   }
 
-  if (options?.extensions) {
-    extensions.push(...options.extensions);
-  }
-
   const features: FrontendFeature[] = [
     createFrontendPlugin({
       pluginId: 'test',