Remove unneeded types (#949)

experimental/desktop_photo_search/lib/main.dart

@@ -115,7 +115,7 @@ class UnsplashHomePage extends StatelessWidget {
                         onPhotoSave: (photo) async {
                           final path = await getSavePath(
                             suggestedName: '${photo.id}.jpg',
-                            acceptedTypeGroups: <XTypeGroup>[
+                            acceptedTypeGroups: [
                               XTypeGroup(
                                 label: 'JPG',
                                 extensions: ['jpg'],

experimental/desktop_photo_search/lib/src/widgets/about_dialog.dart

@@ -42,7 +42,7 @@ class PolicyDialog extends StatelessWidget {
                   text: TextSpan(
                     text: '• ',
                     style: const TextStyle(color: Colors.black, fontSize: 18),
-                    children: <TextSpan>[
+                    children: [
                       TextSpan(
                         text: 'https://policies.google.com/terms',
                         style: const TextStyle(
@@ -64,7 +64,7 @@ class PolicyDialog extends StatelessWidget {
                   text: TextSpan(
                     text: '• ',
                     style: const TextStyle(color: Colors.black, fontSize: 18),
-                    children: <TextSpan>[
+                    children: [
                       TextSpan(
                         text: 'https://unsplash.com/terms',
                         style: const TextStyle(
@@ -86,7 +86,7 @@ class PolicyDialog extends StatelessWidget {
           );
         },
       ),
-      actions: <Widget>[
+      actions: [
         TextButton(
           onPressed: () {
             Navigator.of(context).pop();

experimental/desktop_photo_search/lib/src/widgets/photo_search_dialog.dart

@@ -49,7 +49,7 @@ class _PhotoSearchDialogState extends State<PhotoSearchDialog> {
             }
           },
         ),
-        actions: <Widget>[
+        actions: [
           TextButton(
             onPressed: () {
               Navigator.of(context).pop();

experimental/web_dashboard/lib/src/widgets/dialogs.dart

@@ -17,7 +17,7 @@ class NewCategoryDialog extends StatelessWidget {
   Widget build(BuildContext context) {
     return const SimpleDialog(
       title: Text('New Category'),
-      children: <Widget>[
+      children: [
         NewCategoryForm(),
       ],
     );

experimental/web_dashboard/lib/src/widgets/edit_entry.dart

@@ -27,7 +27,7 @@ class _NewEntryFormState extends State<NewEntryForm> {
 
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
-      children: <Widget>[
+      children: [
         Padding(
           padding: const EdgeInsets.all(8.0),
           child: CategoryDropdown(