Merge branch '6.4' into 7.3

* 6.4:
  don't use a fixed date fixture when assertions depend on relative times
  [AssetMapper] Fix parsing @import that don't use url()

Author: xabbuh

Tests/Iterator/RealIteratorTestCase.php

@@ -72,8 +72,8 @@ public static function setUpBeforeClass(): void
         file_put_contents(self::toAbsolute('test.php'), str_repeat(' ', 800));
         file_put_contents(self::toAbsolute('test.py'), str_repeat(' ', 2000));
 
-        touch(self::toAbsolute('foo/bar.tmp'), strtotime('2005-10-15'));
-        touch(self::toAbsolute('test.php'), strtotime('2005-10-15'));
+        touch(self::toAbsolute('foo/bar.tmp'), strtotime('-19 years'));
+        touch(self::toAbsolute('test.php'), strtotime('-19 years'));
 
         if (FinderTest::class === static::class) {
             $fs = new Filesystem();