Upgrade php cs fixer

[biozshock]

Q	A
Bug fix? (use the a.b branch)	[ ]
New feature/enhancement? (use the a.x branch)	[ x ]
Deprecations?	[ ]
BC breaks? (use the c.x branch)	[ ]

Description:

Upgraded codestyle checker PHP-CS-Fixer to latest version.

Steps to test this PR:

1. See github actions are not failing.
2. Do a code review.

[codecov]

Codecov Report

Merging #11548 (598b25e) into 5.x (024d80c) will not change coverage.
The diff coverage is 42.85%.

@@            Coverage Diff            @@
##                5.x   #11548   +/-   ##
=========================================
  Coverage     51.50%   51.50%           
- Complexity    35373    35375    +2     
=========================================
  Files          2144     2144           
  Lines        106485   106485           
=========================================
  Hits          54842    54842           
  Misses        51643    51643           

Impacted Files	Coverage Δ
...m/Validator/Constraints/OAuthCallbackValidator.php	50.00% <ø> (ø)
app/bundles/ApiBundle/Model/ClientModel.php	70.21% <ø> (ø)
...ndles/AssetBundle/EventListener/FormSubscriber.php	25.00% <0.00%> (ø)
...les/AssetBundle/EventListener/ReportSubscriber.php	56.52% <ø> (ø)
app/bundles/CampaignBundle/Entity/Event.php	80.45% <ø> (ø)
...ntListener/CampaignActionJumpToEventSubscriber.php	85.71% <ø> (ø)
.../CampaignBundle/EventListener/ReportSubscriber.php	15.11% <ø> (ø)
...aignBundle/Executioner/Event/ActionExecutioner.php	84.61% <ø> (ø)
...nBundle/Executioner/Event/ConditionExecutioner.php	94.44% <ø> (ø)
...gnBundle/Executioner/Event/DecisionExecutioner.php	33.33% <ø> (ø)
... and 126 more

[escopecz]

I have mixed feelings about this change as this will cause a lot of open PRs to have conflicts and require manual work to get them into mergeable state. When releasing M4 release we have to merge the changes to the 5.x branch which is costly already. Last time I had to resolve around 100 conflicting files. I would appreciate if we wouldn't make it any harder.

On the other hand, we did the same on our fork and it is the way forward. So Let's not stop the progress.

@kuzmany what do you think?

[escopecz]

I rebased this to fix a conflict in composer.lock. I better merge this to avoid other conflicts.