feature #47730 Ban DateTime from the codebase (WebMamba)

This PR was squashed before being merged into the 6.2 branch.

Discussion
----------

Ban DateTime from the codebase

| Q             | A
| ------------- | ---
| Branch?       | 6.2
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | yes
| Tickets       | #47580
| License       | MIT
| Doc PR        | symfony

As discuss in this issue, the purpose of this PR is to remove DateTime from the code base in favor to DateTimeImmutable. I will process it component by component. Feel free to discuss!

Commits
-------

689385a83f Ban DateTime from the codebase

Author: fabpot

Tests/ResponseTest.php

@@ -796,17 +796,17 @@ public function testIsImmutable()
     public function testSetDate()
     {
         $response = new Response();
-        $response->setDate(\DateTime::createFromFormat(\DateTime::ATOM, '2013-01-26T09:21:56+0100', new \DateTimeZone('Europe/Berlin')));
+        $response->setDate(\DateTime::createFromFormat(\DateTimeInterface::ATOM, '2013-01-26T09:21:56+0100', new \DateTimeZone('Europe/Berlin')));
 
-        $this->assertEquals('2013-01-26T08:21:56+00:00', $response->getDate()->format(\DateTime::ATOM));
+        $this->assertEquals('2013-01-26T08:21:56+00:00', $response->getDate()->format(\DateTimeInterface::ATOM));
     }
 
     public function testSetDateWithImmutable()
     {
         $response = new Response();
-        $response->setDate(\DateTimeImmutable::createFromFormat(\DateTime::ATOM, '2013-01-26T09:21:56+0100', new \DateTimeZone('Europe/Berlin')));
+        $response->setDate(\DateTimeImmutable::createFromFormat(\DateTimeInterface::ATOM, '2013-01-26T09:21:56+0100', new \DateTimeZone('Europe/Berlin')));
 
-        $this->assertEquals('2013-01-26T08:21:56+00:00', $response->getDate()->format(\DateTime::ATOM));
+        $this->assertEquals('2013-01-26T08:21:56+00:00', $response->getDate()->format(\DateTimeInterface::ATOM));
     }
 
     public function testSetExpires()