fix(windows): enable WinHTTP IPv6 fast fallback

Dual-stack hostnames with unreachable IPv6 stalled past the endpoint
probe budget because WinHTTP tries addresses sequentially. Enable
WINHTTP_OPTION_IPV6_FAST_FALLBACK (Happy Eyeballs) via win_http 0.2.2
so IPv4 is raced after the IPv6 attempt, matching curl/Cronet/NSURLSession.

close #1128

pubspec.lock

@@ -1473,10 +1473,10 @@ packages:
     dependency: "direct main"
     description:
       name: win_http
-      sha256: a50a14f1bf32bc5c9b39add9baa01658b97146b21de25237810ca6b850a6704e
+      sha256: ebc4d37e2c0e6800cc200e40d289d3bac22fc17d40fce3ae7909d49a20da77bc
       url: "https://pub.dev"
     source: hosted
-    version: "0.2.1"
+    version: "0.2.2"
   window_manager:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -72,7 +72,7 @@ dependencies:
       ref: 9e150f7
   cupertino_http: ^2.4.0
   cronet_http: ^1.6.0
-  win_http: ^0.2.1
+  win_http: ^0.2.2
   collection: ^1.18.0
   freezed_annotation: ^3.1.0
   xml: ^6.6.1