The configuration value `spring.cloud.openfeign.oauth2.clientRegistrationId` is only accepted with CamelCase and not with dash-case

[lucasvc]

Describe the bug
Using spring-cloud-openfeign-core-4.3.0.jar, if the application.yml configuration provides

spring:
  security:
    oauth2:
      client:
        registration:
          fancy:
            client-id: jane.appeo
            client-secret: ${env:SUPER_SECRET}
            provider: fancy-authserver
            authorization-grant-type: client_credentials
        provider:
          fancy-authserver:
            token-uri: http://localhost:9999
  cloud:
    openfeign:
      oauth2:
        enabled: true
        clientRegistrationId: fancy

When the configuration spring.cloud.openfeign.oauth2.clientRegistrationId is set with CamelCase it is matched correctly, but when using spring.cloud.openfeign.oauth2.client-registration-id with dash-case the identifier is not matched when creating the OAuth2AccessTokenInterceptor at FeignAutoConfiguration#defaultOAuth2AccessTokenInterceptor.

Sample
This was found debugging some kind of test. I will try provide later a full test with the situation