After some more analysis I found out, that the packaging process starts to generate a ton of “pakchunk0_s{number}.txt” files (about 100 per second) into the directory “{GameDir}\Saved\TmpPackaging\WindowsNoEditor” but all theses files have a size of 0KB!
Addionally in this directory there is also a “pakchunklist.txt” that contains references to all the generated 0KB files.