Remove value conversion to DateTime in ConstraintValidator

[norkunas]

Q	A
Branch?	master
Bug fix?	no
New feature?	no
Deprecations?	no
Tickets	-
License	MIT
Doc PR	-

IntlDateFormatter supports formatting DateTimeImmutable instances since php 7.1.5, so we don't need anymore to convert it to DateTime instance when formatting values in ConstraintValidator.
https://3v4l.org/jW5CM

[fancyweb]

That's true and symfony/intl halso supports it now (see #32947). At the moment this change kind of conflict with #34904. However, that means I can use \DateTimeImmutable there.

[norkunas]

That's true and symfony/intl halso supports it now (see #32947). At the moment this change kind of conflict with #34904. However, that means I can use \DateTimeImmutable there.

Sorry, missed this :)

[fancyweb]

Keep this one open for now.

However, that means I can use \DateTimeImmutable there

Actually not sure it worth it to check the PHP version and symfony/intl for that...

[fancyweb]

I think this PR can be closed because #34904 was merged. A new \DateTime instance is now formatted. Using a \DateTimeImmutable instead would not change anything.

[norkunas]

But what's the point of reconstructing another instance?

[fancyweb]

To force the formatted \DateTime timezone to UTC.

[norkunas]

Ok 👍