fixed DefaultFlatParamObject to work with annotated parameters. Fixes…

[uc4w6c]

fix #2181

Since there is no test code in the repository from before, I don't know why it is doing annotation checks.
However, since the target parameter can be determined by AbstractRequestService.isRequestTypeToIgnore, I would like to remove the annotation retention confirmation process.

Related PR: https://github.com/springdoc/springdoc-openapi/pull/1805/files

[Charles7c]

I am looking forward to updating.

[bnasslahsen]

@uc4w6c,

Thank you for your contribution to the project!

[NaccOll]

@Charles7c @uc4w6c
DefaultFlatParamObject is what I added to reduce the usage of ParameterObject. Stopping automatic flattening of objects when annotations are found is itself an expected behavior, because when I annotate an object, I don't want him to be flattened (like @RequestBody, @RequestPart). If you want to add annotations to keep things flat, you should add configuration to ignore specified annotations instead of removing this code directly. Because of this pr, there are problems with all methods using @RequestBody and @RequestPart at present, and the document cannot be displayed correctly