(events): Unable to use content based filtering patterns in detailType

### Describe the bug

When using the L2 construct for EventBridge Rules a type failure occurs when attempting to create an event bridge rule that uses [content based filtering patterns](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-event-patterns-content-based-filtering.html). Requiring the use of a trapdoor in order to achieve the desired results.

### Expected Behavior

Content based filtering patterns are supported in an events detailType

### Current Behavior

Type '{ prefix: string; }' is not assignable to type 'string'

### Reproduction Steps

```
#!/usr/bin/env node
import 'source-map-support/register';
import * as cdk from 'aws-cdk-lib';
import { Rule, CfnRule } from 'aws-cdk-lib/aws-events';

const app = new cdk.App();

const stack = new cdk.Stack(app, 'RuleTestStack');

const rule = new Rule(stack, 'Rule', {
eventPattern: {
detailType: [{"prefix": "shared_"}]
}
});

```

### Possible Solution

See https://github.com/aws/aws-cdk/pull/30222

Using a trapdoor does provide a work around

```
(rule.node.defaultChild as CfnRule).addOverride('Properties.EventPattern.detail-type', [{"prefix": "shared_"}])
```

### Additional Information/Context

_No response_

### CDK CLI Version

2.141.0

### Framework Version

_No response_

### Node.js Version

18.18.0

### OS

OSX

### Language

TypeScript

### Language Version

Typescript 5.4.0

### Other information

_No response_

Start in the aws-events Rule eventPattern types, focusing on detailType and the CfnRule override shown in the report. Confirm the type accepts content-based filtering objects such as {"prefix":"shared_"}, then verify that the example can synthesize without using a trapdoor.

Written by the indexing model from the issue text.