[dartdev] Update dependencies of 'web' template

Primarily updates package:web past v1 to avoid usages of the major deprecation removals.

Change-Id: Iadf614c533a043ba3821d241548cc47a68a30558
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/421500
Reviewed-by: Srujan Gaddam <[email protected]>
Reviewed-by: Ben Konyi <[email protected]>
Auto-Submit: Parker Lougheed <[email protected]>
Commit-Queue: Srujan Gaddam <[email protected]>

Author: parlough

pkg/dartdev/lib/src/templates/web.dart

@@ -50,11 +50,11 @@ environment:
 
 # Add regular dependencies here.
 dependencies:
-  web: ^0.5.1
+  web: ^1.1.1
 
 dev_dependencies:
-  build_runner: ^2.4.8
-  build_web_compilers: ^4.0.9
+  build_runner: ^2.4.15
+  build_web_compilers: ^4.1.4
   lints: ^5.0.0
 ''';
 
@@ -113,7 +113,7 @@ import 'package:web/web.dart' as web;
 void main() {
   final now = DateTime.now();
   final element = web.document.querySelector('#output') as web.HTMLDivElement;
-  element.text =
+  element.textContent =
       'The time is \${now.hour}:\${now.minute} '
       'and your Dart web app is running!';
 }