panic: The environment variable "SYSTEM_NAMESPACE" is not set

	If this is a process running on Kubernetes, then it should be using the downward
	API to initialize this variable via:

	  env:
	  - name: SYSTEM_NAMESPACE
	    valueFrom:
	      fieldRef:
	        fieldPath: metadata.namespace

	If this is a Go unit test consuming system.Namespace() then it should add the
	following import:

	import (
		_ "knative.dev/pkg/system/testing"
	)

goroutine 1 [running]:
knative.dev/pkg/system.Namespace()
	knative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/system/env.go:39 +0x8a
main.main()
	github.com/tektoncd/pipeline/cmd/webhook/main.go:254 +0x285