Remove test_requirements from setup.py

The setup file has been updated to remove the 'tests_require' attribute. Instead, 'test_requirements' has been added under 'extras_require'. This change allows the flexible installation of test requirements.

setup.py

@@ -56,7 +56,6 @@ setup(
     name="cooperative_cuisine",
     packages=find_packages(include=["cooperative_cuisine", "cooperative_cuisine.*"]),
     test_suite="tests",
-    tests_require=test_requirements,
     url="https://gitlab.ub.uni-bielefeld.de/scs/cocosy/overcooked-simulator",
     version="0.1.0",
     zip_safe=False,
@@ -66,6 +65,7 @@ setup(
             "stable-baselines3[extra]>=2.2.1",
             "opencv-python>=4.9",
             "wandb>=0.16.3",
-        ]
+        ],
+        "test": test_requirements,
     },
 )