Describe the bug

Using Springdoc 3.0.2 with Spring Boot 4.0.3.
When configuring a WebFluxConfigurer for API Versioning and setting VersionRequired to true, Swagger UI fails.
Specifically, the OpenAPI definition endpoint (/v3/api-docs) returns 404 - Not Found.

I have created a reproducer (attached zip file) based on the path-segment branch in the Git repo https://github.com/springdoc/springdoc-openapi-versioning-demo.

I have changed webmvc dependencies to webflux in the pom.xml, and changed the WebMvcConfigurer to a WebFluxConfigurer. To show the error, I have changed:

.setDefaultVersion("1.0")
.setVersionRequired(false)

to:

.setVersionRequired(true)

To Reproduce

Steps to reproduce the behavior:

1. Download an unzip springdoc-webflux-version-requried-error.zip

2. Build, run, and test

   In one terminal:

   cd springdoc-webflux-version-requried-error
   ./mvnw spring-boot:run
   

   In another terminal:

   # Expect 200 - OK responses from these reqiuests
   curl localhost:8080/api/v1.0/users
   curl localhost:8080/api/2.0/users
   curl http://localhost:8080/swagger-ui/index.html
   
   # These requests will fail with 404 - Not Found
   curl http://localhost:8080/v3/api-docs/swagger-config
   curl http://localhost:8080/v3/api-docs
   

3. Open Swagger UI (http://localhost:8080/swagger-ui/index.html), it will show the error message: "Failed to load remote configuration."

4. Change back to not requiring an API version, and Swagger UI starts to work again, including the two failed requests above.

Expected behavior

• A working Swagger UI when using WebFlux and requiring API Versions to be specified.