Merge branch '6.4' into 7.0

* 6.4:
  fix compatibility with Redis Relay 0.8.1
  use more entropy with uniqid()
  [Cache] Improve `dbindex` DSN parameter parsing
  Support for PHP-CS-Fixer's parallel runner
  use more entropy with uniqid()
  [Contracts][HttpClient] Skip tests when zlib's `ob_gzhandler()` doesn't exist

Author: xabbuh

Tests/CacheWarmer/ConfigBuilderCacheWarmerTest.php

@@ -37,7 +37,7 @@ class ConfigBuilderCacheWarmerTest extends TestCase
 
     protected function setUp(): void
     {
-        $this->varDir = sys_get_temp_dir().'/'.uniqid();
+        $this->varDir = sys_get_temp_dir().'/'.uniqid('', true);
         $fs = new Filesystem();
         $fs->mkdir($this->varDir);
     }