Use super.key instead of manually passing the Key parameter to the parent class (#147621)

*Use `super.key` instead of manually passing the `Key` parameter using super(key: key) in the constructors.*

Since if you create a widget the new default will use `super.key` instead of `Key? key : super(key: key)` this small change is to maintain the consistency, it has no semantic change

also there are some other places that might need to be updated:

![image](https://github.com/flutter/flutter/assets/73608287/898f62f5-10f9-4d76-a46c-6def328177cb)

this file for example generate l10n project and it has all the dart code as String, it might have tests that validate the output somewhere that I might miss, also there are some other places like the `_Segment` class where it require `ValueKey` instead if `Key` so I didn't update them (even though it's possible)

examples/api/lib/widgets/scroll_view/list_view.1.dart

@@ -74,9 +74,9 @@ class _ListViewExampleState extends State<ListViewExample> {
 
 class KeepAliveItem extends StatefulWidget {
   const KeepAliveItem({
-    required Key key,
+    required Key super.key,
     required this.data,
-  }) : super(key: key);
+  });
 
   final String data;
 

packages/flutter/lib/src/widgets/dismissible.dart

@@ -97,7 +97,7 @@ class Dismissible extends StatefulWidget {
   /// dismissed item. Using keys causes the widgets to sync according to their
   /// keys and avoids this pitfall.
   const Dismissible({
-    required Key key,
+    required Key super.key,
     required this.child,
     this.background,
     this.secondaryBackground,
@@ -112,8 +112,7 @@ class Dismissible extends StatefulWidget {
     this.crossAxisEndOffset = 0.0,
     this.dragStartBehavior = DragStartBehavior.start,
     this.behavior = HitTestBehavior.opaque,
-  }) : assert(secondaryBackground == null || background != null),
-       super(key: key);
+  }) : assert(secondaryBackground == null || background != null);
 
   /// The widget below this widget in the tree.
   ///

packages/flutter/lib/src/widgets/overlay.dart

@@ -273,11 +273,11 @@ class OverlayEntry implements Listenable {
 
 class _OverlayEntryWidget extends StatefulWidget {
   const _OverlayEntryWidget({
-    required Key key,
+    required Key super.key,
     required this.entry,
     required this.overlayState,
     this.tickerEnabled = true,
-  }) : super(key: key);
+  });
 
   final OverlayEntry entry;
   final OverlayState overlayState;

packages/flutter/lib/src/widgets/reorderable_list.dart

@@ -1050,11 +1050,11 @@ class SliverReorderableListState extends State<SliverReorderableList> with Ticke
 
 class _ReorderableItem extends StatefulWidget {
   const _ReorderableItem({
-    required Key key,
+    required Key super.key,
     required this.index,
     required this.child,
     required this.capturedThemes,
-  }) : super(key: key);
+  });
 
   final int index;
   final Widget child;

packages/flutter/lib/src/widgets/unique_widget.dart

@@ -22,9 +22,7 @@ abstract class UniqueWidget<T extends State<StatefulWidget>> extends StatefulWid
   ///
   /// The [key] argument is required because it identifies the unique inflated
   /// instance of this widget.
-  const UniqueWidget({
-    required GlobalKey<T> key,
-  }) : super(key: key);
+  const UniqueWidget({required GlobalKey<T> super.key});
 
   @override
   T createState();

packages/flutter/test/widgets/automatic_keep_alive_test.dart

@@ -9,7 +9,7 @@ import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 class Leaf extends StatefulWidget {
-  const Leaf({ required Key key, required this.child }) : super(key: key);
+  const Leaf({ required Key super.key, required this.child });
   final Widget child;
   @override
   State<Leaf> createState() => _LeafState();
@@ -584,7 +584,7 @@ void main() {
 }
 
 class _AlwaysKeepAlive extends StatefulWidget {
-  const _AlwaysKeepAlive({ required Key key }) : super(key: key);
+  const _AlwaysKeepAlive({ required Key super.key });
 
   @override
   State<StatefulWidget> createState() => _AlwaysKeepAliveState();

packages/flutter/test/widgets/binding_deferred_first_frame_test.dart

@@ -88,7 +88,7 @@ void main() {
 }
 
 class _DeferringWidget extends StatefulWidget {
-  const _DeferringWidget({required Key key, required this.loader}) : super(key: key);
+  const _DeferringWidget({required Key super.key, required this.loader});
 
   final Future<void> loader;
 

packages/flutter/test/widgets/reparent_state_test.dart

@@ -24,7 +24,7 @@ class StateMarkerState extends State<StateMarker> {
 }
 
 class DeactivateLogger extends StatefulWidget {
-  const DeactivateLogger({ required Key key, required this.log }) : super(key: key);
+  const DeactivateLogger({ required Key super.key, required this.log });
 
   final List<String> log;