Revert "[BUGFIX] Skip main extension repository check in Composer mode"

This reverts commit e538ed3f.

We do need the information about the main repository status as there is
currently no other possibility to get information about the (security)
status of extension besides the TER itself.

Resolves: #79285
Related: #79277
Releases: master, 7.6
Change-Id: Ia769dc95eaeff405f291d5929b7790a50c332a83
Reviewed-on: https://review.typo3.org/51280


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>