When debug is not turned on correctly, redundant volumes appear

[yang kewei]

Actual Behavior

I turned on debug mode on our platform, but did not fill in the specific fields,
resulting in debug.breakpoints.onFailure being empty. At this time, the debug
mode is not actually turned on correctly. I noticed some issues.

1. When debug is not turned on correctly, volumes related to debug mode appear.
2. Tips can be added to prevent incorrect setting of debug mode.

Steps to Reproduce the Problem

1. The following is the simplest example.

apiVersion: tekton.dev/v1
kind: TaskRun
metadata:
  name: debug-example
spec:
  debug:
    breakpoints:
      onFailure: ""
  taskSpec:
    steps:
    - image: centos7:release
      imagePullPolicy: Always
      name: start-debug
      script: |
        echo "hello"

Additional Info

tekton: 0.53.0

[yang kewei]

/assign