Migrate from deprecated github-label-sync to @endbug/github-label-sync (#323)

* Initial plan

* Migrate from github-label-sync to @endbug/github-label-sync

Agent-Logs-Url: https://github.com/EndBug/label-sync/sessions/de132f6d-cd7b-4edd-88f7-fff8672081ab

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

Author: Copilot

lib/index.js

@@ -24,13 +24,12 @@
   "homepage": "https://github.com/EndBug/label-sync#readme",
   "dependencies": {
     "@actions/core": "^1.10.1",
+    "@endbug/github-label-sync": "^3.0.0",
     "axios": "^1.15.2",
-    "github-label-sync": "^2.3.1",
     "js-yaml": "^4.1.1",
     "pretty-error": "^4.0.0"
   },
   "devDependencies": {
-    "@types/github-label-sync": "^2.3.3",
     "@types/js-yaml": "^4.0.9",
     "@types/node": "^24.0.0",
     "@typescript-eslint/eslint-plugin": "^8.56.1",

package-lock.json

@@ -0,0 +1,56 @@
+declare module '@endbug/github-label-sync' {
+  export interface BasicLabel {
+    name: string;
+    color: string;
+    description?: string | undefined;
+  }
+
+  export interface LabelInfo extends BasicLabel {
+    aliases?: string[] | undefined;
+    delete?: boolean | undefined;
+  }
+
+  export interface OptionsBase {
+    allowAddedLabels?: boolean | undefined;
+    dryRun?: boolean | undefined;
+    format?:
+      | {
+          diff?: ((str: string) => string) | undefined;
+          success?: ((str: string) => string) | undefined;
+          warning?: ((str: string) => string) | undefined;
+        }
+      | undefined;
+    labels: LabelInfo[];
+    log?:
+      | {
+          info?: ((str: string) => void) | undefined;
+          warn?: ((str: string) => void) | undefined;
+        }
+      | undefined;
+  }
+
+  export interface Options extends OptionsBase {
+    accessToken: string;
+    repo: string;
+    endpoint?: string | undefined;
+  }
+
+  export interface DefaultOptions extends Required<OptionsBase> {
+    accessToken: null;
+    endpoint: null;
+    repo: null;
+  }
+
+  export interface LabelDiff {
+    name: string;
+    type: string;
+    actual?: BasicLabel | undefined;
+    expected?: BasicLabel | undefined;
+  }
+
+  export const defaults: DefaultOptions;
+
+  export default function githubLabelSync(
+    options: Options
+  ): Promise<LabelDiff[]>;
+}

package.json

@@ -2,7 +2,7 @@ import * as PrettyError from 'pretty-error';
 PrettyError.start();
 
 import * as core from '@actions/core';
-import githubLabelSync, {LabelInfo, Options} from 'github-label-sync';
+import githubLabelSync, {LabelInfo, Options} from '@endbug/github-label-sync';
 import * as fs from 'fs';
 import * as path from 'path';
 import * as yaml from 'js-yaml';