Log trigger not recognized if intervalSeconds is not set despite it being marked as optional

[jmcclell]

Describe the bug
When defining a sensor that uses the log trigger, failing to define intervalSeconds results in an invalid trigger error.

{"level":"error","ts":1740540329.7287948,"logger":"argo-events.sensor","caller":"sensors/listener.go:395","msg":"Failed to execute a trigger","sensorName":"log-github-events","error":"inv
alid trigger log, could not find an implementation","triggerName":"log","triggeredBy":["github-event"],"triggeredByEvents":["6dbfaeac648b446f9e3162361daeb07a"],"stacktrace":"github.com/ar
goproj/argo-events/pkg/sensors.(*SensorContext).triggerWithRateLimit\n\t/home/runner/work/argo-events/argo-events/pkg/sensors/listener.go:395\ngithub.com/argoproj/argo-events/pkg/sensors.
(*SensorContext).triggerActions.func1\n\t/home/runner/work/argo-events/argo-events/pkg/sensors/listener.go:376"}

To Reproduce
Steps to reproduce the behavior:

Create a sensor of the form:

apiVersion: argoproj.io/v1alpha1
kind: Sensor
metadata:
  name: my-sensor
spec:
  dependencies:
    - name: my-source
      eventSourceName: my-event-source
      eventName: my-event
  triggers:
    - template:
        name: my-trigger
        log: ~ 

Expected behavior
I expect that the mere presence of the log key would translate to a working log trigger given its only sub-key is meant to be optional.

While this isn't a terribly consequential bug, it was the cause of some frustration as a new user. Especially as I did not intend to make use of the interval functionality.

Environment (please complete the following information):

• Kubernetes: 1.31
• Argo Events: 1.9.5

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