[flutter_tool] Remove some async file io (#38654)

https://dart.googlesource.com/external/github.com/flutter/flutter/+/398ac1f6c892bc3638c08f1aef0bfbd99d8418c3
1 file changed
tree: ddf303919e8cad5e1b31b6d718bb309d5d579c23
  1. commits.json