Merge branch '6.4' into 7.1

* 6.4:
  relax format assertions for fstat() results on Windows
  update ICU data from 75.1 to 76.1
  fix referencing the SYMFONY_VERSION env var
  handle error results of DateTime::modify()

Author: xabbuh

Tests/Constraints/TimezoneValidatorTest.php

@@ -69,10 +69,6 @@ public static function getValidTimezones(): iterable
         yield ['America/Argentina/Buenos_Aires'];
 
         // not deprecated in ICU
-        yield ['CST6CDT'];
-        yield ['EST5EDT'];
-        yield ['MST7MDT'];
-        yield ['PST8PDT'];
         yield ['America/Toronto'];
 
         // previously expired in ICU