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

Inline.php

@@ -699,7 +699,7 @@ private static function evaluateScalar(string $scalar, int $flags, array &$refer
                         return (float) str_replace('_', '', $scalar);
                     case Parser::preg_match(self::getTimestampRegex(), $scalar):
                         // When no timezone is provided in the parsed date, YAML spec says we must assume UTC.
-                        $time = new \DateTime($scalar, new \DateTimeZone('UTC'));
+                        $time = new \DateTimeImmutable($scalar, new \DateTimeZone('UTC'));
 
                         if (Yaml::PARSE_DATETIME & $flags) {
                             return $time;

Tests/InlineTest.php

@@ -573,10 +573,10 @@ public function testParseTimestampAsUnixTimestampByDefault(string $yaml, int $ye
      */
     public function testParseTimestampAsDateTimeObject(string $yaml, int $year, int $month, int $day, int $hour, int $minute, int $second, int $microsecond, string $timezone)
     {
-        $expected = new \DateTime($yaml);
-        $expected->setTimeZone(new \DateTimeZone('UTC'));
-        $expected->setDate($year, $month, $day);
-        $expected->setTime($hour, $minute, $second, $microsecond);
+        $expected = (new \DateTime($yaml))
+            ->setTimeZone(new \DateTimeZone('UTC'))
+            ->setDate($year, $month, $day)
+            ->setTime($hour, $minute, $second, $microsecond);
 
         $date = Inline::parse($yaml, Yaml::PARSE_DATETIME);
         $this->assertEquals($expected, $date);
@@ -598,10 +598,10 @@ public function getTimestampTests(): array
      */
     public function testParseNestedTimestampListAsDateTimeObject(string $yaml, int $year, int $month, int $day, int $hour, int $minute, int $second, int $microsecond)
     {
-        $expected = new \DateTime($yaml);
-        $expected->setTimeZone(new \DateTimeZone('UTC'));
-        $expected->setDate($year, $month, $day);
-        $expected->setTime($hour, $minute, $second, $microsecond);
+        $expected = (new \DateTime($yaml))
+            ->setTimeZone(new \DateTimeZone('UTC'))
+            ->setDate($year, $month, $day)
+            ->setTime($hour, $minute, $second, $microsecond);
 
         $expectedNested = ['nested' => [$expected]];
         $yamlNested = "{nested: [$yaml]}";
@@ -636,7 +636,7 @@ public function getDateTimeDumpTests()
     {
         $tests = [];
 
-        $dateTime = new \DateTime('2001-12-15 21:59:43', new \DateTimeZone('UTC'));
+        $dateTime = new \DateTimeImmutable('2001-12-15 21:59:43', new \DateTimeZone('UTC'));
         $tests['date-time-utc'] = [$dateTime, '2001-12-15T21:59:43+00:00'];
 
         $dateTime = new \DateTimeImmutable('2001-07-15 21:59:43', new \DateTimeZone('Europe/Berlin'));

Tests/ParserTest.php

@@ -1546,10 +1546,10 @@ public function testParseDateAsMappingValue()
         $yaml = <<<'EOT'
 date: 2002-12-14
 EOT;
-        $expectedDate = new \DateTime();
-        $expectedDate->setTimeZone(new \DateTimeZone('UTC'));
-        $expectedDate->setDate(2002, 12, 14);
-        $expectedDate->setTime(0, 0, 0);
+        $expectedDate = (new \DateTimeImmutable())
+            ->setTimeZone(new \DateTimeZone('UTC'))
+            ->setDate(2002, 12, 14)
+            ->setTime(0, 0, 0);
 
         $this->assertSameData(['date' => $expectedDate], $this->parser->parse($yaml, Yaml::PARSE_DATETIME));
     }