[BUGFIX] Disable dump autoloading in Composer mode

This patch hides the "Dump autoload" button in the maintenance area when
in Composer mode, because it does nothing.

Resolves: #86565
Releases: master
Change-Id: Ib8f71f5a41189f97f02aed6b4c7cb69feabef724
Reviewed-on: https://review.typo3.org/58578


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Torben Hansen <derhansen@gmail.com>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Tomas Norre Mikkelsen <tomasnorre@gmail.com>
Reviewed-by: Tobi Kretschmann <tobi@tobishome.de>
Tested-by: Tobi Kretschmann <tobi@tobishome.de>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>