[BUGFIX] CLI execution fatals

Upstream phpunit removed PHPUnit/Autoload.php and relies on composer
autoloading. ext_localconf.php already includes the composer autoload
stuff, so a require_once on PHPUnit/Autoload.php is obsolete.
The patch removes this line and fixes a fatal error by require_once
this way.

Resolves: #59973
Related: #59797
Change-Id: I3bb377b3997e44e4282d1d4ea1b30e18adffcb9d
Reviewed-on: https://review.typo3.org/31213
Reviewed-by: Oliver Klee
Tested-by: Oliver Klee