* fixed : add doc blocks to silence Symfony deprecations

Symfony 5.4 returning deprecations about 
```
User Deprecated: Method "Twig\Extension\ExtensionInterface::getFunctions()" might add "array" as a native return type declaration in the future.
Do the same in implementation "Nelmio\ApiDocBundle\Render\Html\GetNelmioAsset" now to avoid errors or add an explicit @return annotation to suppress this message.
```

* fixed : native hint

* add zircore/swagger-php v4 to composer.json

* fix incompatibilities

* add compatibility with 3.2

* Apply fixes from StyleCI

* mark SetsContextTrait as internal

* Bump php version

Co-authored-by: Alexey <alshenestky@icloud.com>
Co-authored-by: Alexey Alshenetsky <alshenetsky@users.noreply.github.com>
Co-authored-by: Guilhem Niot <guilhem@gniot.fr>

* Adding ``header_block`` Twig Block

In attempting to remove the default green header from the API docs (I am integrating the docs into a site that already has a header), I have found that the only possible way to do so is to overwrite the entire ``index.html.twig`` file.  This is because the existing ``{% header %}`` twig tags are placed *inside* the ``<header>`` HTML tags.  So, if one overrides the ``{% header %}`` block, it only adjusts the header content, as opposed to allowing control over the entire header object.

To resolve this problem I considered two methods:

- Move the existing ``{% header %}`` tags _*outside*_ of the ``<header>`` tags.  This would resolve the problem in the simplest fashion, but would be a breaking change for those currently overriding the block.

- Add a new twig block, placing its tags *_outside_* the existing ``<header>`` tags.  This would leave the existing functionality as-is, and would not break any current implementations.

I chose the latter for the reasons specified above, and suggested the name ``{% header_block %}``.  Thanks for considering this proposal.

* Add Location of Original Twig Template

This doc page advises that one can `have a look at the original template to see which blocks can be overridden`, but does not say where the original template can be found.  This edit adds that information so that users don't have to resort to searching for keywords (like I just had to).

Note that I haven't run any tests as this is a docs-only change.

…elmio#1918)

* add null check

nelmio#1909

* less code is better

* add tests for ControllerReflection::getReflectionMethod()

* lint fix

* style_ci fixes

Co-authored-by: Alexey <alshenestky@icloud.com>

…ort to symfony < 5.3

…dependencies' into feature/1913-upgrate-symfony-60-dependencies

# Conflicts:
#	.github/workflows/continuous-integration.yml
#	composer.json