[proxy-agent] Use "lru-cache@8"

ncc v0.24.0 has an issue parsing "lru-cache@9" :/

```
ncc: Version 0.24.0
ncc: Compiling file index.js
ncc: Using typescript@4.9.5 (local user-provided)
Error: Module parse failed: Unexpected token (27:15)
File was processed with these loaders:
 * ../../node_modules/.pnpm/@vercel+ncc@0.24.0/node_modules/@vercel/ncc/dist/ncc/loaders/empty-loader.js
 * ../../node_modules/.pnpm/@vercel+ncc@0.24.0/node_modules/@vercel/ncc/dist/ncc/loaders/relocate-loader.js
 * ../../node_modules/.pnpm/@vercel+ncc@0.24.0/node_modules/@vercel/ncc/dist/ncc/loaders/shebang-loader.js
You may need an additional loader to handle the result of these loaders.
|     //@ts-ignore
|     AS = class AbortSignal {
>         onabort;
|         _onabort = [];
|         reason;
```

packages/proxy-agent/package.json

@@ -40,7 +40,7 @@
     "debug": "^4.3.4",
     "http-proxy-agent": "^5.0.0",
     "https-proxy-agent": "^5.0.1",
-    "lru-cache": "^9.1.1",
+    "lru-cache": "^8.0.5",
     "pac-proxy-agent": "^5.0.0",
     "proxy-from-env": "^1.1.0",
     "socks-proxy-agent": "^7.0.0"