refactor: apply review suggestions

Signed-off-by: Camila Belo <camilaibs@gmail.com>

.changeset/famous-crabs-laugh.md

@@ -1,6 +1,5 @@
 ---
 '@backstage/backend-common': patch
-'@backstage/plugin-scaffolder-node': patch
 ---
 
 Preparing for a stable new backend system release, we are deprecating utilities in the `backend-common` that are not used by the core framework, such as the isomorphic `Git` class. As we will no longer support the isomorphic `Git` utility in the framework packages, we recommend plugins that start maintaining their own implementation of this class.

.changeset/strange-rocks-study.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-node': patch
+---
+
+To remove the dependency on the soon-to-be-deprecated `backend-common` package, this package now maintains its own isomorphic Git class implementation.

packages/backend-common/src/reading/GerritUrlReader.ts

@@ -45,13 +45,7 @@ import {
   SearchResponse,
   UrlReader,
 } from './types';
-import { StaticAuthOptions, AuthCallbackOptions, Git } from './git';
-
-export function isAuthCallbackOptions(
-  options: StaticAuthOptions | AuthCallbackOptions,
-): options is AuthCallbackOptions {
-  return 'onAuth' in options;
-}
+import { Git } from './git';
 
 const pipeline = promisify(pipelineCb);
 

packages/backend-common/src/reading/git.ts

@@ -18,7 +18,6 @@ import fs from 'fs-extra';
 import isomorphicGit, { ProgressCallback, AuthCallback } from 'isomorphic-git';
 import http from 'isomorphic-git/http/node';
 import { LoggerService } from '@backstage/backend-plugin-api';
-import { isAuthCallbackOptions } from './GerritUrlReader';
 
 /**
  * Configure static credential for authentication
@@ -42,6 +41,12 @@ export type AuthCallbackOptions = {
   logger?: LoggerService;
 };
 
+function isAuthCallbackOptions(
+  options: StaticAuthOptions | AuthCallbackOptions,
+): options is AuthCallbackOptions {
+  return 'onAuth' in options;
+}
+
 /*
 provider          username         password
 Azure             'notempty'       token