[21052] Remove public ChangeForReader* from api reference

[Mario-DL]

Description

This PR removes some public api reference regarding ChangeForReader* that is no longer available.

Related implementation PR:

• [21052] Make ChangeForReader, ReaderLocator, ReaderProxy private Fast-DDS#4923

Contributor Checklist

• Commit messages follow the project guidelines.
• Code snippets related to the added documentation have been provided.
• Documentation tests pass locally.
• NO Applicable backports have been included in the description.

Reviewer Checklist

• The PR has a milestone assigned.
• The title and description correctly express the PR's purpose.
• Check contributor checklist is correct.
• CI passes without warnings or errors.

[Mario-DL]

@richiprosima please test_3 docs