[TASK] Add dev-main branch alias

In preparation of renaming the main development branch,
the alias for the new name is added.

This makes it possible to rename the branch and have
a working alias, without needing to add further commits to it.

composer up --lock

Releases: master
Resolves: #96102
Change-Id: Id01c6d562a2bdd0c42a7b6ad69019b19181c94ee
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/72325


Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>