Prior to this commit, the AnnotationsScanner used in the
MergedAnnotations infrastructure found duplicate annotations on methods
within multi-level interface hierarchies.
This commit addresses this issue by scanning methods at a given level
in the interface hierarchy using ReflectionUtils#getDeclaredMethods
instead of Class#getMethods, since the latter includes public methods
declared in super-interfaces which will anyway be scanned when
processing super-interfaces recursively.
Closes gh-31803
(cherry picked from commit 75da9c3c47)