🗑️ chore: Remove YouTube API integration (#11331)

* 🗑️ refactor: Remove YouTube API integration and related configurations as it's broken and should be integrated via MCP instead. Currently there seems not to be a single MCP out there with working get_transcript methods for months. API seems to have changed and there are no maintainers on these projects. We will work out something soon an MCP solution

- Deleted YouTube API key and related configurations from .env.example.
- Removed YouTube tools and their references from the API client, including the manifest and structured files.
- Updated package.json to remove YouTube-related dependencies.
- Cleaned up toolkit exports by removing YouTube toolkit references.

* chore: revert package removal to properly remove packages

* 🗑️ refactor: Remove YouTube API and related dependencies due to integration issues

---------

Co-authored-by: Danny Avila <danny@librechat.ai>

api/package.json

@@ -43,7 +43,6 @@
     "@azure/search-documents": "^12.0.0",
     "@azure/storage-blob": "^12.27.0",
     "@google/genai": "^1.19.0",
-    "@googleapis/youtube": "^20.0.0",
     "@keyv/redis": "^4.3.3",
     "@langchain/core": "^0.3.80",
     "@librechat/agents": "^3.0.77",
@@ -112,7 +111,6 @@
     "undici": "^7.10.0",
     "winston": "^3.11.0",
     "winston-daily-rotate-file": "^5.0.0",
-    "youtube-transcript": "^1.2.1",
     "zod": "^3.22.4"
   },
   "devDependencies": {