Remove unnecessary os and sys imports.

tests/1.C/test_task2.py

-import pytest, os, sys # type: ignore
+import pytest
 
 import src.swinging as main
 

tests/1.C/test_task3.py

 from vpython import vector, color, textures
-import pytest, os, sys # type: ignore
+import pytest
 
 from tests.helpers.fake_objects import FakePend
 import src.swinging as main

tests/2.B/test_task4.py

-import pytest, os, sys # type: ignore
+import pytest
 import visualize_cradle_run as main
 
 @pytest.mark.parametrize("e, omega, omega2, m1, m2, r_param, expected_omega, expected_omega2", [

tests/2.B/test_task5.py

-import pytest, os, sys # type: ignore
+import pytest
 from vpython import vector, color, textures
 
 import visualize_cradle_run as main

tests/3.A/test_task6.py

-import pytest, os, sys # type: ignore
+import pytest
 from vpython import vector, color, textures
 
 import visualize_cradle_run as main
@@ -10,7 +10,7 @@ from tests.helpers.fake_objects import FakePend
                             r_param, dt, g, \
                             exp_omega1, exp_theta1, \
                             exp_omega2, exp_theta2, \
-                            exp_omega3, exp_theta3",[
+                            exp_omega3, exp_theta3", [
     ((vector(1, 0, 0), 1, 0.5, 2, 1,
       vector(0, 0, 0), 2, 0.5, 3, 0,
       vector(1.05, 0, 0), 1, 0.5, 2.5, 1,

tests/helpers/constants_for_testing.py

 from vpython import vector
-import pytest, os, sys  # type: ignore
 
 VPYTHON_COLOR_MAP = {
     'white': vector(1,1,1),