This reverts commit 8e73bab9.

* update pinned null safety deps

* run update-packages

* add http dep to devicelab package

* rerun update-packages

This reverts commit dd9323bd.

- - When I added notification of key events before processing them as text, it made it so that shortcut key bindings like the spacebar would prevent spaces from being inserted into text fields, which is obviously not desirable (and so that change was reverted). At the same time, we do want to make it possible to override key events so that they can do things like intercept a tab key or arrow keys that change the focus.

This PR changes the behavior of the Shortcuts widget so that if it has a shortcut defined, but no action is bound to the intent, then instead of responding that the key is "handled", it responds as if nothing handled it. This allows the engine to continue to process the key as text entry.

This PR includes:

- Modification of the callback type for key handlers to return a KeyEventResult instead of a bool, so that we can return more information (i.e. the extra state of "stop propagation").
- Modification of the ActionDispatcher.invokeAction contract to require that Action.isEnabled return true before calling it. It will now assert if the action isn't enabled when invokeAction is called. This is to allow optimization of the number of calls to isEnabled, since the shortcuts widget now wants to know if the action was enabled before deciding to either handle the key or to return ignored.
- Modification to ShortcutManager.handleKeypress to return KeyEventResult.ignored for keys which don't have an enabled action associated with them.
- Adds an attribute to DoNothingAction that allows it to mark a key as not handled, even though it does have an action associated with it. This will allow disabling of a shortcut for a subtree.

The Dart SDK now requires non-null enum values if the enum is used in an
exhaustive switch statement on a non-nullable type.

See https://github.com/flutter/flutter/issues/66674

Updates all null safe dependencies to versions that allow 2.10 stable and 2.11 dev releases.

Also updates flutter_goldens and flutter_goldens_client to allow 2.11 dev.

Remove fake image implementations, add createTestImage to flutter_test

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

Fix the `character` field of the `RawKeyEvent` to hold correct data on non-Android platforms. (#65667)

This fixes a problem where the character field of the RawKeyEvent was not being set at all for non-Android platforms.

I also updated the key maps, and corrected a problem with the Windows key map where the backquote character wasn't correctly mapped.

This reverts commit 5b3dc525.

This reverts commit c46aa360.

This reverts commit b7b60a2d.

Revert "Reland "Add support for Dart Development Service (DDS) in Flutter Tools (#61276)" (#61633)" (#61641)

This reverts commit 594c3541.

This reverts commit a1a5a8f6.

Roll packages, update XML deprecations.

Update all versions, specifically file which fixes some bugs that caused tests to fail if run in different orders:

- systemTemp directories created by MemoryFileSystem will allot names based on the file system instance instead of globally.
- MemoryFile.readAsLines()/readAsLinesSync() no longer treat a final newline in the file as the start of a new, empty line.
- RecordingFile.readAsLine()/readAsLinesSync() now always record a final newline.

Fixes #59718

Update all versions, specifically dwds which has a hot restart fix