[SDS-826] unused package braaks nightly (#153)

.github/workflows/nightly.yaml

@@ -3,7 +3,6 @@ name: Nightly SDK build
 on:
   schedule:
     - cron: "59 23 * * 1-5"
-  push:
 
 jobs:
   test:

setup.py

@@ -60,7 +60,7 @@ def get_long_description():
       license='Apache 2.0',
       packages=['quantuminspire', 'quantuminspire.qiskit', 'quantuminspire.projectq'],
       install_requires=['coverage>=4.5.1', 'matplotlib>=2.1', 'pylatexenc', 'coreapi>=2.3.3', 'numpy>=1.20', 'jupyter',
-                        'nbimporter', 'sklearn', 'qilib'],
+                        'nbimporter', 'qilib'],
       extras_require={
           'qiskit': ["qiskit>=0.20.0"],
           'projectq': ["projectq>=0.4"],