User's defined cloud stream binder are not recognized by AOT stage

[petretiandrea]

Describe the issue
This introduce a bug where AOT doesn't recognize user defined binders.

spring-cloud-stream/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binder/BinderChildContextInitializer.java

Line 111 in f811ed0

.bind("spring.cloud.stream.binders", Bindable.ofInstance(bindingServiceProperties));

Given this configuration the AOT pre-creates only "kafka" (the default one) not for test1 and test2

spring:
    cloud:
        function:
            definition: test1;test2
        stream:
            default-binder: test1
            bindings:
                test1-in-0:
                    destination: topic-test-1
                    group: topic-test1-group
                    binder: test1
                test2-in-0:
                    destination: topic-test-2
                    group: topic-test2-group
                    binder: test2
            binders:
              test1:
                type: kakfa
              test2:
                type: kakfa

By editing the configuration in this way:

spring:
    cloud:
        function:
            definition: test1;test2
        stream:
            default-binder: test1
            bindings:
                test1-in-0:
                    destination: topic-test-1
                    group: topic-test1-group
                    binder: test1
                test2-in-0:
                    destination: topic-test-2
                    group: topic-test2-group
                    binder: test2
            binders:
              binders:
                test1:
                  type: kakfa
                test2:
                  type: kakfa

Yes, with two binders keyword, the AOT pre-creates test1 and test2.

I'm doing something wrong or is an unexpected bug?

To Reproduce
Try to use this simple cloud stream configuration

spring:
    cloud:
        function:
            definition: test1;test2
        stream:
            default-binder: test1
            bindings:
                test1-in-0:
                    destination: topic-test-1
                    group: topic-test1-group
                    binder: test1
                test2-in-0:
                    destination: topic-test-2
                    group: topic-test2-group
                    binder: test2
            binders:
              test1:
                type: kakfa
              test2:
                type: kakfa

Version of the framework
2023.0.0-SNAPSHOT
Expected behavior
No two binders keywork required and AOT recognize user defined binders.
Screenshots

Additional context
Add any other context about the problem here.