Remove unused pytest-timeout dependency (#19)

Author: blueraft

pyproject.toml

@@ -22,7 +22,6 @@ homepage = "https://github.com/nomad-coe/database-parsers"
 [project.optional-dependencies]
 tests = [
     "pytest>= 5.3.0, <= 8.0.2",
-    "pytest-timeout==1.4.2",
     "pytest-cov==2.7.1",
     "astroid>=2.5.1",
     'mypy==1.0.1',