Delete windows.yml

```
Run go build -a -o _output/azurediskplugin.exe ./pkg/azurediskplugin
##[error]pkg\azurediskplugin\main.go:30:2: cannot find package "k8s.io/component-base/metrics/legacyregistry" in any of:
	C:\hostedtoolcache\windows\go\1.14.3\x64\src\k8s.io\component-base\metrics\legacyregistry (from $GOROOT)
	C:\Users\runneradmin\go\src\k8s.io\component-base\metrics\legacyregistry (from $GOPATH)
##[error]pkg\azurediskplugin\main.go:31:2: cannot find package "k8s.io/klog" in any of:
	C:\hostedtoolcache\windows\go\1.14.3\x64\src\k8s.io\klog (from $GOROOT)
	C:\Users\runneradmin\go\src\k8s.io\klog (from $GOPATH)
##[error]pkg\azurediskplugin\main.go:28:2: cannot find package "sigs.k8s.io/azuredisk-csi-driver/pkg/azuredisk" in any of:
	C:\hostedtoolcache\windows\go\1.14.3\x64\src\sigs.k8s.io\azuredisk-csi-driver\pkg\azuredisk (from $GOROOT)
	C:\Users\runneradmin\go\src\sigs.k8s.io\azuredisk-csi-driver\pkg\azuredisk (from $GOPATH)
##[error]Process completed with exit code 1.
```