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.