add a label for policy endpoint refer to its mapped Network Policy (#45)

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improvement
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**What does this PR do / Why do we need it**:
We want to add a label to new created Policy Endpoint. The label refers
to the parent network policy and will be used by node agent.

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Makefile

@@ -170,7 +170,7 @@ $(MOCKGEN): $(LOCALBIN)
 	test -s $(MOCKGEN) || GOBIN=$(LOCALBIN) go install github.com/golang/mock/[email protected]
 
 GOARCH=amd64
-BUILD_IMAGE=public.ecr.aws/docker/library/golang:1.20.6
+BUILD_IMAGE=public.ecr.aws/docker/library/golang:1.21.3
 BASE_IMAGE=public.ecr.aws/eks-distro-build-tooling/eks-distro-minimal-base-nonroot:latest.2
 GO_RUNNER_IMAGE=public.ecr.aws/eks-distro/kubernetes/go-runner:v0.15.0-eks-1-27-3
 .PHONY: docker-buildx

pkg/policyendpoints/manager.go

@@ -23,6 +23,10 @@ import (
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/resolvers"
 )
 
+const (
+	LabelKeyToParentPolicyName = "networking.k8s.io/parent-network-policy-name"
+)
+
 type PolicyEndpointsManager interface {
 	Reconcile(ctx context.Context, policy *networking.NetworkPolicy) error
 	Cleanup(ctx context.Context, policy *networking.NetworkPolicy) error
@@ -298,6 +302,9 @@ func (m *policyEndpointsManager) newPolicyEndpoint(policy *networking.NetworkPol
 					Controller:         &isController,
 				},
 			},
+			Labels: map[string]string{
+				LabelKeyToParentPolicyName: policy.Name,
+			},
 		},
 		Spec: policyinfo.PolicyEndpointSpec{
 			PodSelector:          &policy.Spec.PodSelector,