Not possible to exclude the `flowable-event-registry` JAR even if EventRegistry disabled

## Describe the bug

Even when disabling the **EventRegistry** via:
```properties
flowable.eventregistry.enabled = false
```
(see [`@ConditionalOnEventRegistry`](https://github.com/flowable/flowable-engine/blob/90b4b509821d3c0ab0051b2be311afbd158da8db/modules/flowable-spring-boot/flowable-spring-boot-starters/flowable-spring-boot-autoconfigure/src/main/java/org/flowable/spring/boot/condition/ConditionalOnEventRegistry.java) and its usage)

and / or via:
```java
@Bean
EngineConfigurationConfigurer customConfig() {
return spec -> spec.setDisableEventRegistry(true);
}
```
it's still not possible to exclude from dependencies the following JAR:

- `flowable-event-registry`

due to a missing check of whether the **EventRegistry** is disabled in:

https://github.com/flowable/flowable-engine/blob/90b4b509821d3c0ab0051b2be311afbd158da8db/modules/flowable-engine/src/main/java/org/flowable/engine/impl/cfg/ProcessEngineConfigurationImpl.java#L1683

thus not bypassing the instantiation of:

https://github.com/flowable/flowable-engine/blob/90b4b509821d3c0ab0051b2be311afbd158da8db/modules/flowable-engine/src/main/java/org/flowable/engine/impl/cfg/ProcessEngineConfigurationImpl.java#L1688

## Expected behavior

```gherkin
When the "EventRegistry" is "disabled" (via a property or a java code)
Then it's possible to exclude from dependencies the "flowable-event-registry" JAR
```
Most likely via bypassing the instantiation of the [`BpmnEventRegistryEventConsumer`](https://github.com/flowable/flowable-engine/blob/90b4b509821d3c0ab0051b2be311afbd158da8db/modules/flowable-engine/src/main/java/org/flowable/engine/impl/eventregistry/BpmnEventRegistryEventConsumer.java) in such a case.

## Code

Currently, we are forced to apply a dummy work-around, such as:
```java
@Bean
EngineConfigurationConfigurer customConfig() {
return spec -> spec.setDisableEventRegistry(true)
.setEventRegistryEventConsumer(noopEventRegistryEventConsumer());
}

private static EventRegistryEventConsumer noopEventRegistryEventConsumer() {
return new EventRegistryEventConsumer() {
@Override
public EventRegistryProcessingInfo eventReceived(EventRegistryEvent event) {
return null;
}

@Override
public String getConsumerKey() {
return "noopEventConsumer";
}
};
}
```
thus bypassing the instantiation of the [`BpmnEventRegistryEventConsumer`](https://github.com/flowable/flowable-engine/blob/90b4b509821d3c0ab0051b2be311afbd158da8db/modules/flowable-engine/src/main/java/org/flowable/engine/impl/eventregistry/BpmnEventRegistryEventConsumer.java) in:
https://github.com/flowable/flowable-engine/blob/90b4b509821d3c0ab0051b2be311afbd158da8db/modules/flowable-engine/src/main/java/org/flowable/engine/impl/cfg/ProcessEngineConfigurationImpl.java#L1683-L1692

For comparison, the IDM engine's inclusion is properly checked in:
https://github.com/flowable/flowable-engine/blob/90b4b509821d3c0ab0051b2be311afbd158da8db/modules/flowable-engine/src/main/java/org/flowable/engine/impl/cfg/ProcessEngineConfigurationImpl.java#L1676-L1681

## Additional context
**Flowable** branches:
- `flowable-release-7.0.0` (tested v. `7.0.1`)
- `flowable-release-7.1.0`
- `main`

**Spring Boot** used in the version declared by the respective **Flowable** version.

relevant exclusions & dependencies in `build.gradle`:
```gradle
configurations.all {
excludeRules += [
[ group: 'org.flowable', module: 'flowable-cmmn-model' ],
[ group: 'org.flowable', module: 'flowable-dmn-model' ],
[ group: 'org.flowable', module: 'flowable-event-registry' ],
[ group: 'org.flowable', module: 'flowable-event-registry-configurator' ],
[ group: 'org.flowable', module: 'flowable-event-registry-model' ],
[ group: 'org.flowable', module: 'flowable-idm-engine' ],
[ group: 'org.flowable', module: 'flowable-idm-engine-configurator' ],
[ group: 'org.yaml', module: 'snakeyaml' ],
]
}

dependencies {
implementation (
[ group: 'org.flowable', name: 'flowable-http' ],
[ group: 'org.flowable', name: 'flowable-secure-javascript' ],
[ group: 'org.flowable', name: 'flowable-spring-boot-starter-process',
exclude: [ group: 'org.flowable', module: 'flowable-event-registry-spring-configurator' ] ],
)
}
```

Bắt đầu tại modules/flowable-engine/src/main/java/org/flowable/engine/impl/cfg/ProcessEngineConfigurationImpl.java, khoảng các dòng 1676-1692, sau đó đọc ConditionalOnEventRegistry và BpmnEventRegistryEventConsumer. So sánh đường đi của EventRegistry với kiểm tra bao gồm IDM. Hoàn thành khi việc vô hiệu hóa EventRegistry bằng property hoặc cấu hình không còn khởi tạo consumer, cho phép loại trừ flowable-event-registry.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.