Remove unused type parameter from ExtensionPointFactoryMiddleware

The generic is no longer needed since the interface is opaque. Type
inference is handled by createExtensionPointFactoryMiddleware instead.

Signed-off-by: Jack Palmer <jackpalmer@spotify.com>

packages/backend-app-api/report.api.md

@@ -47,7 +47,7 @@ export interface BackendStartupResult {
 export function createExtensionPointFactoryMiddleware<T>(options: {
   extensionPoint: ExtensionPoint<T>;
   middleware: (original: T) => Promise<T>;
-}): ExtensionPointFactoryMiddleware<T>;
+}): ExtensionPointFactoryMiddleware;
 
 // @public (undocumented)
 export function createSpecializedBackend(
@@ -63,7 +63,7 @@ export interface CreateSpecializedBackendOptions {
 }
 
 // @public
-export interface ExtensionPointFactoryMiddleware<_T = unknown> {
+export interface ExtensionPointFactoryMiddleware {
   // (undocumented)
   $$type: '@backstage/ExtensionPointFactoryMiddleware';
 }

packages/backend-app-api/src/wiring/types.ts

@@ -29,7 +29,7 @@ import { OpaqueExtensionPointFactoryMiddleware } from '@internal/backend';
  *
  * @public
  */
-export interface ExtensionPointFactoryMiddleware<_T = unknown> {
+export interface ExtensionPointFactoryMiddleware {
   $$type: '@backstage/ExtensionPointFactoryMiddleware';
 }
 
@@ -42,7 +42,7 @@ export interface ExtensionPointFactoryMiddleware<_T = unknown> {
 export function createExtensionPointFactoryMiddleware<T>(options: {
   extensionPoint: ExtensionPoint<T>;
   middleware: (original: T) => Promise<T>;
-}): ExtensionPointFactoryMiddleware<T> {
+}): ExtensionPointFactoryMiddleware {
   return OpaqueExtensionPointFactoryMiddleware.createInstance('v1', {
     extensionPointId: options.extensionPoint.id,
     middleware: options.middleware as (original: unknown) => Promise<unknown>,