Hot restart hangs periodically in webdev and flutter CI

[annagrin]

Examples

• Webdev:
  Fix intermittent broken sockets on connection to asset server. #1353, in particular:
  https://github.com/dart-lang/webdev/runs/3109885465

• Possibly related in Flutter:
  Web hot restart tests flaky timeout frequently causing web_tool_tests failure flutter/flutter#85043