Merge branch '6.0' into 6.1

* 6.0:
  Use mb_convert_encoding instead of utf8_decode
  [SecurityBundle] Remove forgotten unused code
  Minor @requires function tests cleanup
  [FrameworkBundle] Always add CacheCollectorPass
  Fix "Notice: Undefined index: headers" in messenger with Oracle
  [String] Fix ansi escape sequences regex
  Indicate support for doctrine/persistence 3
  [Routing] fix router base url when default uri has trailing slash
  Replace deprecated String.prototype.substr()

Author: derrabus

AbstractUnicodeString.php

@@ -478,7 +478,7 @@ public function width(bool $ignoreAnsiDecoration = true): int
         foreach (explode("\n", $s) as $s) {
             if ($ignoreAnsiDecoration) {
                 $s = preg_replace('/(?:\x1B(?:
-                    \[ [\x30-\x3F]*+ [\x20-\x2F]*+ [0x40-\x7E]
+                    \[ [\x30-\x3F]*+ [\x20-\x2F]*+ [\x40-\x7E]
                     | [P\]X^_] .*? \x1B\\\\
                     | [\x41-\x7E]
                 )|[\p{Cc}\x7F]++)/xu', '', $s);