[ci] Remove device_type property from Windows Arm64 properties (flutt…

…er#5193)

The Windows Arm64 tests are failing to start as no machines match desired properties. This removes the `device_type: none` property as no Windows Arm64 machines match this ([with `device_type`](https://chromium-swarm.appspot.com/botlist?c=id&c=task&c=os&c=status&d=asc&f=cpu%3Aarm64&f=os%3AWindows&f=pool%3Aluci.flutter.staging&f=device_type%3Anone&s=id), [without `device_type`](https://chromium-swarm.appspot.com/botlist?c=id&c=task&c=os&c=status&d=asc&f=cpu%3Aarm64&f=os%3AWindows&f=pool%3Aluci.flutter.staging&s=id)).

This matches the corresponding framework `.ci.yaml` platform properties, which also omits the `device_type: none` for Windows Arm64: https://github.com/flutter/flutter/blob/997a94fd1f022492b6c955013eeec7e4c4e67c62/.ci.yaml#L192-L209

Part of flutter/flutter#129813

.ci.yaml

@@ -68,7 +68,6 @@ platform_properties:
         [
           {"dependency": "certs", "version": "version:9563bb"}
         ]
-      device_type: none
       os: Windows
       cpu: arm64
   windows_x64: