fix: often exits immediately on launch

[bart-iconica]

Description

Quite often dart_frog dev exits immediately on launch and I can't figure out why this happens. On a fresh PC boot it'll work just fine but once I exit it and then start it again it'll just quit immediately.

$ time dart_frog --verbose dev -p 8081
[meta] dart_frog_cli 1.2.5
[codegen] running pre-gen...
Starting development server on host null
[codegen] running generate...
⠙ Serving... (82ms)[codegen] complete.
[process] dart --enable-vm-service=8181 /workspaces/project/.dart_frog/server.dart
✓ Running on http://localhost:8081 (92ms)
The Dart VM service is listening on http://127.0.0.1:8181/SODhgRSXQmc=/
The Dart DevTools debugger and profiler is available at: http://127.0.0.1:8181/SODhgRSXQmc=/devtools/?uri=ws://127.0.0.1:8181/SODhgRSXQmc=/ws
[process] Server process has been terminated
[process] exit(-9)
[process] killing process...
[process] process.kill()...
[process] killing process complete.
[watcher] cancelling subscription...
[watcher] cancelling subscription complete.
[updater] checking for updates...
[updater] latest version is 1.2.5.
[updater] no updates available.
[updater] update check complete.

________________________________________________________
Executed in    3.04 secs    fish           external
   usr time    4.14 secs    0.00 millis    4.14 secs
   sys time    0.53 secs    2.08 millis    0.53 secs

A workaround is to log out of my machine and back in so I'm guessing there is some cache lingering around that needs clearing for some reason.

ps aux reveals no other Dart process is running while this is happening.

Steps To Reproduce

1. Launch dart_frog dev
2. Quit it (Ctrl + C)
3. Launch it again

Expected Behavior

dart_frog dev to always launch and keep running.

Additional Context

I'm using devcontainers to run this, although I'm not sure how it would be relevant.