* opt out the flutter tool

* oops EOF

* fix import

* Update tool_backend.dart

* Update daemon_client.dart

* fix more

[flutter_tools] use initially parsed package config for language version, sound mode determination (#70323)

Fixes #69348

If the web development server fails to bind, then retry up to 5 times. If a port was not provided, select a new free port each time.

Support --web-renderer options which would allow user to specify which rendering backend to use. (#68848)

Rolls in several fixes to web tooling, including better handling of absolute file imports. Updates to latest vm service to unblock null safety mode query
Co-authored-by: Gary Roumanis <grouma@google.com>
Co-authored-by: Anna Gringauze <annagrin@google.com>

* [flutter_tools] null safety mode is used for dill naming

* add bad test case

* Respond to POST with 404 in WebAssetServer

HACKTOBERFEST

If the vm of an attached device rejects a hot reload, pretty print the reason. Suggest a hot restart so that users are aware that they do not have to detach and rebuild. Also resets the last compilation time, so a subsequent restart would still apply the last change. Adds an integration test for the const field removal.

Fixes #64027

Do not upload all assets on initial devFS sync. This should increase the reliability of the initial connection, even in the face of flaky devfs behavior, in addition to a moderate perf improvement.

Updates fast-start to build assets as part of the initial bundle

Requires flutter/engine#21436
Requires flutter/engine#21586
Requires flutter/engine#21611