[BUGFIX] Fix extraction path of language packs in LanguagePackService

[BUGFIX] Fix extraction path of language packs in LanguagePackService

Due to the appended extension key an invalid directory structure was
created. The language pack ".zip" files already contain extension
directories.

Resolves: #84638
Releases: master
Related: #84131
Change-Id: I19d4fa418a5c09a88fb814fb0780e122655a24b0
Reviewed-on: https://review.typo3.org/56577
Reviewed-by: Tim Schreiner <schreiner.tim@gmail.com>
Tested-by: Tim Schreiner <schreiner.tim@gmail.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>