[TASK] Use semver for Symfony versions

Symfony has one of the best BC promises in the PHP world. Which means it
will be never a problem to allow all new minor versions of a supported
major release, even if there are deprecations. Deprecations don't infer
with existing code.

Resolves: #77983
Resolves: #76118
Related: #73517
Releases: master, 7.6
Change-Id: I221bb61674b3e4aaa7676d0929dae2ec18e01627
Reviewed-on: https://review.typo3.org/49965


Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Helmut Hummel <typo3@helhum.io>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>