No body available for Build events

### Jenkins and plugins versions report

The plugin sends the event to http sink but the body is empty and following error is thrown in Jenkins
```
enkins | 2023-05-30 03:23:06.949+0000 [id=245] INFO i.j.p.cloudevents.sinks.HTTPSink#sendCloudEvent: Received response: 404
jenkins | com.fasterxml.jackson.databind.JsonMappingException: Cannot invoke "java.util.Date.getTime()" because "this.createdDate" is null (through reference chain: io.jenkins.plugins.cloudevents.model.JobModel["createdDate"])
jenkins | at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:390)
jenkins | at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:349)
jenkins | at com.fasterxml.jackson.databind.ser.std.StdSerializer.wrapAndThrow(StdSerializer.java:316)
jenkins | at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:778)
jenkins | at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178)
jenkins | at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480)
jenkins | at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319)
jenkins | at com.fasterxml.jackson.databind.ObjectMapper._writeValueAndClose(ObjectMapper.java:4485)
jenkins | at com.fasterxml.jackson.databind.ObjectMapper.writeValueAsString(ObjectMapper.java:3740)
jenkins | at io.jenkins.plugins.cloudevents.CloudEventsUtil.convertToJson(CloudEventsUtil.java:16)
jenkins | at io.jenkins.plugins.cloudevents.sinks.HTTPSink.buildCloudEvent(HTTPSink.java:38)
jenkins | at io.jenkins.plugins.cloudevents.sinks.HTTPSink.sendCloudEvent(HTTPSink.java:57)
jenkins | at io.jenkins.plugins.cloudevents.Stage.handleEvent(Stage.java:38)
jenkins | at io.jenkins.plugins.cloudevents.listeners.CEJobListener.onFinalized(CEJobListener.java:30)
jenkins | at hudson.model.listeners.RunListener.lambda$fireFinalized$3(RunListener.java:244)
jenkins | at jenkins.util.Listeners.lambda$notify$0(Listeners.java:59)
jenkins | at jenkins.util.Listeners.notify(Listeners.java:67)
jenkins | at hudson.model.listeners.RunListener.fireFinalized(RunListener.java:242)
jenkins | at hudson.model.Run.onEndBuilding(Run.java:2062)
jenkins | at org.jenkinsci.plugins.workflow.job.WorkflowRun.finish(WorkflowRun.java:663)
jenkins | at org.jenkinsci.plugins.workflow.job.WorkflowRun$GraphL.onNewHead(WorkflowRun.java:1065)
jenkins | at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.notifyListeners(CpsFlowExecution.java:1587)
jenkins | at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$3.run(CpsThreadGroup.java:509)
jenkins | at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$1.run(CpsVmExecutorService.java:38)
jenkins | at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:139)
jenkins | at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
jenkins | at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
jenkins | at jenkins.util.ErrorLoggingExecutorService.lambda$wrap$0(ErrorLoggingExecutorService.java:51)
jenkins | at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
jenkins | at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
jenkins | at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
jenkins | at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
jenkins | at java.base/java.lang.Thread.run(Thread.java:833)
jenkins | Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Date.getTime()" because "this.createdDate" is null
jenkins | at io.jenkins.plugins.cloudevents.model.JobModel.getCreatedDate(JobModel.java:90)
jenkins | at jdk.internal.reflect.GeneratedMethodAccessor417.invoke(Unknown Source)
jenkins | at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
jenkins | at java.base/java.lang.reflect.Method.invoke(Method.java:568)
jenkins | at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:689)
jenkins | at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:770)
jenkins | ... 29 more
```

Environment

```text
Jenkins: 2.387.3
OS: Linux - 5.4.0-1103-azure
Java: 17.0.7 - Eclipse Adoptium (OpenJDK 64-Bit Server VM)
```
Plugin:
```text
cloudevents:1.0.0
```

### What Operating System are you using (both controller, and any agents involved in the problem)?

NA

### Reproduction steps

1. In global config, set up an http sink in CloudEvents plugin
2. Enable `Job Started`, `Job Completed`, `Job Finalized`
3. Create a freestyle project and run the pipeline
4. Check the http sink endpoint, it would have received request without body

### Expected Results

HttpSink to receive request with body object similar to below, as mentioned in https://github.com/jenkinsci/cloudevents-plugin#build-events
```
{
"userId": "SYSTEM",
"userName": "SYSTEM",
"name": "test2",
"displayName": "test2",
"url": "job/test2/",
"build": {
"fullUrl": "http://3.101.116.80/job/test2/13/",
"number": 13,
"queueId": 25,
"timestamp": 1626611053632,
"duration": 0,
"phase": "STARTED",
"status": null,
"url": "job/test2/13/",
"displayName": null,
"parameters": {
"IsSCM": "true"
},
"scmState": {
"url": "https://github.com/ShrutiC-git/scmConfig.git",
"branch": "origin/main",
"commit": "218c63f230732c6d561fefd00fd0d2ac4ded1a0c"
}
}
}
```

### Actual Results

HttpSink to receive request `without` body object

### Anything else?

_No response_