Revert "jk no venv"

This reverts commit 457e2844cd3ea0458a09aa0123876824a239abcb.

ml-agents/tests/yamato/yamato_utils.py

     if mlagents_python_version:
         venv_path += "_" + mlagents_python_version
 
-    # Set up the venv (mac only) and install mlagents
-    if platform == "darwin":
-        subprocess.check_call(f"python3 -m venv {venv_path}", shell=True)
+    # Set up the venv and install mlagents
+    if platform == "linux":
+        subprocess.check_call("sudo apt-get install -y python3-venv", shell=True)
+
+    subprocess.check_call(f"python3 -m venv {venv_path}", shell=True)
     pip_commands = ["--upgrade pip", "--upgrade setuptools"]
     if mlagents_python_version:
         # install from pypi