Update UnityFileSystemApi to 6000.6.0a7

Replace update to builds extracted from 6000.6.0a7

* Windows was extracted by installing and copying file from C:\Program Files\Unity 6000.6.0a7\Editor\Data\Tools
* Linux was extracted from Unity-6000.6.0a7.tar.xz from Unity-6000.6.0a7.tar.xz\Unity-6000.6.0a7.tar\Editor\Data\Tools\ (Using 7z)
* OSX was extracted from ARM64 build Unity-6000.6.0a7.pkg from Unity.pkg.tmp\Payload\Payload~\.\Unity\Unity.app\Contents\Frameworks\ (Using 7z)

Author: SkowronskiAndrew