RFR: 8177100: APIs duplicated in JavaDoc [v7]

[Nizar Benalla]

> Please review this patch to fix a bug where a method can be documented multiple times 
> Consider these 4 classes
> 
>                     A       (interface)
>                    / \
>                   /   \
> (abstract class)  C     B   ( interface)
>                   \   /
>                    \ /
>                     D       (class)
> 
> 
> Where `A` declares `testA()`, `C` implements it `public final void testA()`, `B` extends `A` but does *not* override it, `D` extends `C` and implements `B`
> 
> In the generated javadoc, `testA()` is documented twice.
> 
> ![Screenshot 2025-05-08 at 15 51 19](https://github.com/user-attachments/assets/46538e61-1546-4128-8041-296d8491406f)
> 
> After the patch, `testA()` is only documented once:
> 
> ![Screenshot 2025-05-08 at 15 52 16](https://github.com/user-attachments/assets/a6b86a21-7104-460c-8f3f-36cee5962eed)

Nizar Benalla has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 14 additional commits since the last revision:

 - Feedback from @hns -  Expand test with new test cases
 - Merge branch 'master' into duplicate-APIs
 - revert back to simple earlier fix
 - revert back to master
 - Merge branch 'master' into duplicate-APIs
 - Merge branch 'master' into duplicate-APIs
 - rename test to be more accurate and simplify code
 - update javadoc
 - Merge branch 'master' into duplicate-APIs
 - new approach - make sure there is no negative effect on JDK doc output
 - ... and 4 more: https://git.openjdk.org/jdk/compare/2b6d4491...caeb20ad

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/25123/files
  - new: https://git.openjdk.org/jdk/pull/25123/files/b53817df..caeb20ad

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25123&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25123&range=05-06

  Stats: 3417 lines in 146 files changed: 2689 ins; 307 del; 421 mod
  Patch: https://git.openjdk.org/jdk/pull/25123.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25123/head:pull/25123

PR: https://git.openjdk.org/jdk/pull/25123