Drop PHP7.0 hacks

src/Monolog/DateTimeImmutable.php

@@ -23,29 +23,9 @@ class DateTimeImmutable extends \DateTimeImmutable implements \JsonSerializable
 
     public function __construct($useMicroseconds, \DateTimeZone $timezone = null)
     {
-        static $needsMicrosecondsHack = PHP_VERSION_ID < 70100;
-
         $this->useMicroseconds = $useMicroseconds;
-        $date = 'now';
-
-        if ($needsMicrosecondsHack && $useMicroseconds) {
-            $timestamp = microtime(true);
-
-            // apply offset of the timezone as microtime() is always UTC
-            if ($timezone && $timezone->getName() !== 'UTC') {
-                $timestamp += (new \DateTime('now', $timezone))->getOffset();
-            }
-
-            // Circumvent DateTimeImmutable::createFromFormat() which always returns \DateTimeImmutable instead of `static`
-            // @link https://bugs.php.net/bug.php?id=60302
-            //
-            // So we create a DateTime but then format it so we
-            // can re-create one using the right class
-            $dt = self::createFromFormat('U.u', sprintf('%.6F', $timestamp));
-            $date = $dt->format('Y-m-d H:i:s.u');
-        }
 
-        parent::__construct($date, $timezone);
+        parent::__construct('now', $timezone);
     }
 
     public function jsonSerialize(): string