Revert "[infra] Temporarily remove windows builder from the CQ"

This reverts commit 95fab34cdf81a45c6c213f62088dd4983ffe6b9d.

Reason for revert: https://crbug.com/840836 is fixed.

Original change's description:
> [infra] Temporarily remove windows builder from the CQ
> 
> TBR=whesse@google.com
> 
> Change-Id: I78eedc9ecfaead1823fcb2d0d204fe4c31b9cad7
> Reviewed-on: https://dart-review.googlesource.com/54224
> Reviewed-by: Alexander Thomas <athom@google.com>

TBR=whesse@google.com,athom@google.com

Change-Id: Iba974cd634a404fd977c8cdd50bf00600cb2bb84
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/54380
Reviewed-by: Alexander Thomas <athom@google.com>
diff --git a/tools/infra/config/cq.cfg b/tools/infra/config/cq.cfg
index 65a9882..2bf13e2 100644
--- a/tools/infra/config/cq.cfg
+++ b/tools/infra/config/cq.cfg
@@ -21,7 +21,7 @@
       name: "luci.dart.try"
       builders { name: "analyzer-linux-release-strong-hostchecked-try" }
       builders { name: "benchmark-linux-try" }
-      builders { name: "dart-sdk-windows-try" experiment_percentage: 100 }
+      builders { name: "dart-sdk-windows-try" }
       builders { name: "dart2js-linux-d8-hostchecked-try" }
       builders { name: "dart2js-linux-d8-kernel-minified-try" }
       builders { name: "dart2js-linux-none-only-unittest-try" }