[TASK] Update Fluid engine to 2.6.4

Addresses the following issues:

* Fixes an annotation that makes phpdocumentor/reflection-docblock
  throw exceptions in TYPO3v10.
* Removes deprecation warning from composer due
  to incorrectly cased package name.
* Fixes issues with binary characters in compiled templates.
* Supports overloaded methods for variable extraction.
* Avoids signature issues with CompileWithRenderStatic.
* Works around PCRE regression issues on affected platforms.

Change-Id: I2b766ccc9bf3eaae77b1dfc1a73e9acc2a88d8a9
Resolves: #89110
Releases: master, 9.5, 8.7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61642


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>