Parent step‘s status is “skipped” but its child step was still executed

**To Reproduce**

yaml
```
apiVersion: core.oam.dev/v1alpha1
kind: WorkflowRun
metadata:
name: test-tgt
namespace: default
annotations:
workflowrun.oam.dev/debug: "true"
spec:
mode:
steps: StepByStep
subSteps: StepByStep
workflowSpec:
steps:
- name: mig-group
type: step-group
if: input.mock == true
subSteps:
- name: read-pod
type: read-pod
properties:
namespace: appworkflow
podName: hdfsjournalnode-286nr-0
```
cue:
```
import (
"vela/op"
)

"read-pod": {
alias: ""
annotations: {}
attributes: {}
description: ""
labels: {}
type: "workflow-step"
}

template: {
parameter: {
podName: string
namespace: string
}
read: op.#Read & {
value: {
kind: "Pod"
apiVersion: "v1"
metadata: {
name: parameter.podName
namespace: parameter.namespace
}
}
}

}

```

**Expected behavior**

**Screenshots**


**Workflow Version**
v0.4.2

**Cluster information**


Start with the provided WorkflowRun YAML, focusing on the step-group condition and the subSteps execution and status handling. Reproduce the behavior against workflow version v0.4.2 and trace why read-pod runs when the parent is skipped; done means skipped parents no longer execute their child steps.

Written by the indexing model from the issue text.