Performance page slow to load on Linux

Dev tools peformance tab takes over 10 seconds to load, compared to just 2 seconds for observatory

[launch-performance-tab-devtools.webm](https://github.com/flutter/devtools/assets/381137/ab49803c-36ac-4843-a628-c9c49658ff8b)

[observatory-timeline-launch.webm](https://github.com/flutter/devtools/assets/381137/632e6dd8-5d34-4e58-a144-291ced2b4063)

This is on a simple dart app:
```
$ cat i1.dart
main() {
Future.delayed(Duration(seconds :5), () { print('elapsed'); });
```

launched like
```
$ out/ReleaseX64/dart --observe:8080 --disable-service-auth-codes --timeline_streams=all --timeline-recorder=endless --serve-observatory i1.dart
```

Devtools app launched separately, connected to this dart app paused.

Reproduce the report with the provided i1.dart example and Dart VM launch command, then compare the DevTools Performance tab with the Observatory timeline launch. Trace the Performance tab's loading path and identify the source of the delay. Done means the tab loads substantially faster on Linux without losing its timeline data.

由索引模型根据 Issue 内容生成。