fix propagationWork API issue, preserve unknown fields

Signed-off-by: Kevin Wang <kevinwzf0126@gmail.com>

artifacts/deploy/propagationstrategy.karmada.io_propagationworks.yaml

@@ -48,6 +48,7 @@ spec:
                       description: Manifest represents a resource to be deployed on
                         managed cluster.
                       type: object
+                      x-kubernetes-preserve-unknown-fields: true
                     type: array
                 type: object
             type: object

pkg/apis/propagationstrategy/v1alpha1/work_types.go

@@ -36,6 +36,7 @@ type WorkloadTemplate struct {
 
 // Manifest represents a resource to be deployed on managed cluster.
 type Manifest struct {
+	// +kubebuilder:pruning:PreserveUnknownFields
 	runtime.RawExtension `json:",inline"`
 }