Fix removed symfony deprecations

[filippeb]

Q	A
Type	improvement
BC Break	yes
Fixed issues

Summary

Update minimum package version symfony/http-kernel: 6.4, 7.0

• source dep: symfony/http-foundation: $request->getContentTypeFormat (available from 5.4, 6.2, 7.0)
• test dep: symfony/http-kernel: HttpKernelInterface::MAIN_REQUEST (available from 5.3)
• applied cs rules

[veewee]

$request->getContentTypeFormat is only available from sf 6.2 and is not available in 5.4.

Would it make sense to allow ^6.4|^7.0 only?
People on lower versions can use an older version of this repo.

6.0-6.3 is not supported anymore.
5.4 is still LTS for 2 years, but they can use an older version of this repo without problems.

[filippeb]

That's possible, updated the PR.

[veewee]

@filippeb can you fix the code-style issues