[ci] Enable Windows build-all (#3054)

These tests were added in bringup mode, but never fully enabled.

Part of https://github.com/flutter/flutter/issues/113764
diff --git a/.ci.yaml b/.ci.yaml
index ee4c132..6ffb6e2 100644
--- a/.ci.yaml
+++ b/.ci.yaml
@@ -139,7 +139,6 @@
         ]
 
   - name: Windows windows-build_all_packages master
-    bringup: true
     recipe: packages/packages
     timeout: 30
     properties:
@@ -153,7 +152,6 @@
         ]
 
   - name: Windows windows-build_all_packages stable
-    bringup: true
     recipe: packages/packages
     timeout: 30
     properties: