Attempt to decrease flakyness on windows CI (#4678)

Author: sigurdm

pubspec.lock

@@ -474,4 +474,4 @@ packages:
     source: hosted
     version: "2.2.2"
 sdks:
-  dart: ">=3.8.0 <4.0.0"
+  dart: ">=3.9.0 <4.0.0"

test/check_resolution_up_to_date_test.dart

@@ -86,6 +86,9 @@ void main() {
       exitCode: 0,
     );
 
+    // Timestamp resolution is rather poor especially on windows.
+    await Future<Null>.delayed(const Duration(seconds: 1));
+
     await d.dir(appPath, [
       d.libPubspec(
         'myapp',
@@ -98,9 +101,6 @@ void main() {
       ),
     ]).create();
 
-    // Timestamp resolution is rather poor especially on windows.
-    await Future<Null>.delayed(const Duration(seconds: 1));
-
     await runPub(
       args: ['check-resolution-up-to-date'],
       environment: {'_PUB_TEST_SDK_VERSION': '3.5.0'},