[FrameworkBundle] Add support for route attributes in kernel controller…

[fabpot]

Q	A
Feature PR	symfony/symfony#46115
PR author(s)	@dunglas
Merged in	6.1

[wouterj]

Hi @dunglas. Do you have any time to add this cool functionality to https://symfony.com/doc/current/configuration/micro_kernel_trait.html ? (e.g. by adding a "php-attributes" tab to the first code example and a versionadded saying it is new)