minor #13841 [Maintenance] Add note to UPGRADE file about dropping Symfony 5.2 support (GSadee)
minor #13841 [Maintenance] Add note to UPGRADE file about dropping Symfony 5.2 support (GSadee)

This PR was merged into the 1.10 branch.

Discussion
----------

| Q               | A
| --------------- | -----
| Branch?         | 1.10
| Bug fix?        | no
| New feature?    | no
| BC breaks?      | no
| Deprecations?   | no
| Related tickets | after #13837 
| License         | MIT

Commits
-------

924c863 [Maintenance] Add note to UPGRADE file about dropping Symfony 5.2 support
SyliusBot/Sylius,diimpp/Sylius,Zales0123/Sylius,lchrusciel/Sylius,Zales0123/Sylius,loic425/Sylius,lchrusciel/Sylius,diimpp/Sylius,loic425/Sylius,101medialab/Sylius,101medialab/Sylius,loic425/Sylius,Sylius/Sylius,Zales0123/Sylius,101medialab/Sylius,diimpp/Sylius,Sylius/Sylius,SyliusBot/Sylius,SyliusBot/Sylius,Sylius/Sylius,lchrusciel/Sylius