upgrade to php 7.4

[stephanvierkant]

• Bumped minimum PHP version to 7.4
• Added types to private properties (and removed phpdoc if superfluous)
• Used arrow functions

Fixes #357

[stof]

this also needs to remove the CI job running on PHP 7.3 (the lowest_deps job must not be removed, but updated to PHP 7.4 instead)

[garak]

Can you remove "dev" suffix from sf 5.4 and 6.0 in the build? Also, the "dev deps" should be on PHP 8.1

[garak]

It's OK for me if we manage to solve the last failing test

[garak]

@stephanvierkant any news on this?

[Chris53897]

Thanks for your work @stephanvierkant
Maybe you can make that change to get this PR merged.

The failing tests are because of the deprecation messages with --prefer-lowest argument.
The solution is to bump minimum version of twig to 1.40 => 1.43
"twig/twig": "^1.43 || ^2.9 || ^3.0"

I did bump "psr/container": "^2.0", as we now have php 7.4 (but this is optional)
https://packagist.org/packages/psr/container#2.0.2

I suggest to update phpunit-bridge as well. (php: >=7.1.3) (but this is optional)
"symfony/phpunit-bridge": "^6.0",

https://github.com/Chris53897/KnpMenu/blob/php74/composer.json

Testrun:
https://github.com/Chris53897/KnpMenu/actions/runs/2338296768

[stof]

I did bump "psr/container": "^2.0", as we now have php 7.4

Dropping support for v1 is a bad idea. There is no reason for that in term of maintenance, and it increases the risk of dependency conflicts.

[garak]

LGTM