[BUGFIX] rtehtmlarea user settings are not shown in setup ext

Fix this by adding the suggestion already present in
the ext_emconf.php also to the composer.json.

Resolves: #58694
Releases: 6.2
Change-Id: I9ded17691ed91fce099638bdac4b4f425cb47ea6
Reviewed-on: https://review.typo3.org/30006
Reviewed-by: Loek Hilgersom
Tested-by: Loek Hilgersom
Reviewed-by: Jacco van der Post
Tested-by: Jacco van der Post
Reviewed-by: Fabien Udriot
Tested-by: Fabien Udriot
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers