update toml informatiom

pyproject.toml

 [tool.poetry]
 name = "pykkn"
-version = "1.5.6"
+version = "1.5.8"
 description = "Python port of the matlab library kkn https://git.rwth-aachen.de/nils.preuss/rdm-kraken/"
 license = "Apache-2.0"
 authors = ["Martin Hock <Martin.Hock@fst.tu-darmstadt.de>"]
-maintainers = [
-    "Zhichao Zhang <zhichao.zhang@stud.tu-darmstadt.de>",
-    "Bastian Tigges <bastian.tigges@stud.tu-darmstadt.de>",
-    "Ilyass Afkir <ilyass.afkir@stud.tu-darmstadt.de>",
-    "Berk Calabakan <berk.calabakan@stud.tu-darmstadt.de>",
-    "Konstantin Repp <konstantin.repp@stud.tu-darmstadt.de>",
-    "Stefan Andreas Sauter <stefan_andreas.sauter@stud.tu-darmstadt.de>"
-]
 readme = "README.md"
 homepage = "https://fst-tuda.pages.rwth-aachen.de/public/pykkn/"
 repository = "https://git.rwth-aachen.de/fst-tuda/public/pykkn"