[versions] update to latest source span and roll engine to  4b8477d11573d233e6791204191c0090f733b05d (#66136)

Revert "Ensure VmService instance is disposed after failed direct connection attempt (#66123)" (#66164)

This reverts commit 409e994c.
Co-authored-by: Jenn Magder <magder@google.com>

_attemptServiceConnection in FallbackDiscovery would fail if the root
library URI was not a package URI even if the VM service connection
attempt was successful. This resulted in a VM service connection being
left alive, causing DDS to fail its connection to the VM service.

Updated _attemptServiceConnection to ensure the VM service instance is
disposed after a non-connection related failure and to allow for root
library URIs with a file scheme.

* wrap LicensePage's loading widget with cardColor

* Set AnimatedSwitcer's duration in LicensePage to zero

* Remove AnimatedSwitcher

* Add test code for checking color is same

The main.dart.js bypass is not needed now that we have skipWaiting. Additionally optimize the fetch handler so that resources not in the cache skip the service worker altogether.

Fixes #66068

2abe69c60 Roll Dart SDK from 83365979ea85 to e41a6008746d (1 revision) (flutter/engine#21224) (#65987)

Turn the opt-in default for ThemeData.useTextSelectionTheme to true so that everything uses the new TextSelectionTheme by default.

Removes the template version from the Windows template; the API and
tooling boundary will now be considered stable, so there will no longer
be frequent breaking changes.

Also updates the link for adding desktop support to a project for all
three platforms to reflect the current location.

Fixes https://github.com/flutter/flutter/issues/52748

The engine now has an explicit API for system font changes, rather than
expecting the WM_FONTCHANGE message to be forwarded to the Flutter view.

Adds a VERSIONINFO to Runner.rc in the Windows app template, populated
from the project creation metadata.

Currently the version itself is hard-coded, but it is future-proofed to
allow plumbing the actual version through at build time via preprocessor
defines.

update_dart_sdk.ps1: Ensure Start-BitsTransfer always throws an exception in case of errors (#65929)

[flutter_tools] use flutter tool handler for dwds resources and precache tool pub dependencies (#65814)

If the tool is downloaded from a precompiled snapshot, or if the backing source files in the pub cache are deleted, the dwds debugging functionality will break as the client.js file cannot be located. Instead use the PackageConfig to verify that package location, downloading if it is missing.

Override the dwds middleware to avoid Isolate.resolvePackageUri

Fixes #53644
Fixes #65475

Deprecate VelocityTracker default constructor and added VelocityTracker.withKind constructor (#66043)

We've gotten feedback that the VelocityTracker change was disruptive, though it did not break any of the flutter framework or customer tests. In order to make the change non-breaking, PointerDeviceKind parameter can be made optional.

Nevertheless, this parameter should be provided so that the existing touch handlers can use more accurate gestures on mouse/stylus inputs, so we can encourage this by deprecating the default constructor and pointing users towards the VelocityTracker.withKind constructor that takes a non-optional parameter