Updating subscriptions fails on sequence update

[sonOfRa]

Describe the bug
If a sequence is updated with a new retry configuration the sequence is not successfully updated.

Expected behavior
The sequence is updated successfully

To Reproduce
Knative Kafka Broker needs to be installed: https://github.com/knative-extensions/eventing-kafka-broker

Create sequence:

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: first
spec:
  template:
    spec:
      containers:
        - image: gcr.io/knative-releases/knative.dev/eventing/cmd/appender
          env:
            - name: MESSAGE
              value: " - Handled by 0"

---
apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: second
spec:
  template:
    spec:
      containers:
        - image: gcr.io/knative-releases/knative.dev/eventing/cmd/appender
          env:
            - name: MESSAGE
              value: " - Handled by 1"
---
apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: third
spec:
  template:
    spec:
      containers:
        - image: gcr.io/knative-releases/knative.dev/eventing/cmd/appender
          env:
            - name: MESSAGE
              value: " - Handled by 2"
---
apiVersion: flows.knative.dev/v1
kind: Sequence
metadata:
  name: sequence
spec:
  channelTemplate:
    apiVersion: messaging.knative.dev/v1beta1
    kind: KafkaChannel
    spec:
      numPartitions: 1
      replicationFactor: 3
  steps:
    - ref:
        apiVersion: serving.knative.dev/v1
        kind: Service
        name: first
      delivery:
        backoffDelay: PT1S
        backoffPolicy: linear
        retry: 5
    - ref:
        apiVersion: serving.knative.dev/v1
        kind: Service
        name: second
      delivery:
        backoffDelay: PT1S
        backoffPolicy: linear
        retry: 5
    - ref:
        apiVersion: serving.knative.dev/v1
        kind: Service
        name: third
      delivery:
        backoffDelay: PT1S
        backoffPolicy: linear
        retry: 5

The subscriptions should have been created.

$ kubectl get subscription
NAME                     AGE   READY   REASON
sequence-kn-sequence-0   14s   True    
sequence-kn-sequence-1   14s   True    
sequence-kn-sequence-2   14s   True    

Modify the sequence and update the delivery spec on step 2 -> retry: 7 or something

The sequence update fails and when displaying the sequence yaml, the following entry is displayed in the conditions block

    - lastTransitionTime: "2024-06-20T14:03:00Z"
      message: 'failed to reconcile subscription resource for step: 0 : subscriptions.messaging.knative.dev
        "sequence-kn-sequence-0" is invalid: metadata.resourceVersion: Invalid value:
        0x0: must be specified for an update'
      reason: SubscriptionsNotReady
      status: Unknown
      type: Ready

Knative release version
1.14.3

Additional context
This bug is a followup to #7939. We deployed the 1.14.3 release to a test system and attempted to update a sequence, which is why the reproduction steps are essentially the same as in that report.

[pierDipi]

/assign @Cali0707