backend-test-utils: remove last type parameter for MockInstance

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/quick-weeks-explode.md

@@ -0,0 +1,5 @@
+---
+'@backstage/backend-test-utils': patch
+---
+
+Remove third type parameter used for `MockInstance`, in order to be compatible with older versions of `@types/jest`.

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

@@ -210,10 +210,9 @@ export type ServiceMock<TService> = {
   factory: ServiceFactory<TService>;
 } & {
   [Key in keyof TService]: TService[Key] extends (
-    this: infer This,
     ...args: infer Args
   ) => infer Return
-    ? TService[Key] & jest.MockInstance<Return, Args, This>
+    ? TService[Key] & jest.MockInstance<Return, Args>
     : TService[Key];
 };
 

packages/backend-test-utils/src/next/services/mockServices.ts

@@ -64,10 +64,9 @@ export type ServiceMock<TService> = {
   factory: ServiceFactory<TService>;
 } & {
   [Key in keyof TService]: TService[Key] extends (
-    this: infer This,
     ...args: infer Args
   ) => infer Return
-    ? TService[Key] & jest.MockInstance<Return, Args, This>
+    ? TService[Key] & jest.MockInstance<Return, Args>
     : TService[Key];
 };