run build job on bigger flavor (#4819)

* run build job on bigger flavor

* log to stdout

* skip editor download for training

.yamato/standalone-build-test.yml

   agent:
     type: Unity::VM
     image: package-ci/ubuntu:stable
-    flavor: b1.medium
+    flavor: b1.large
   variables:
     UNITY_VERSION: {{ editor.version }}
   commands:

.yamato/training-int-tests.yml

       sudo apt-get update && sudo apt-get install -y python3-venv
       python3 -m venv venv && source venv/bin/activate
       python -m pip install pyyaml --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple
-      python -m pip install unity-downloader-cli --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple --upgrade
-      unity-downloader-cli -u {{ editor.version }} -c editor --wait --fast
       python -u -m ml-agents.tests.yamato.training_int_tests
   dependencies:
     - .yamato/standalone-build-test.yml#test_linux_standalone_{{ editor.version }}

ml-agents/tests/yamato/standalone_build_tests.py

         output_path=executable_name,
         scene_path=scene_path,
         build_target=build_target,
+        log_output_path=None,  # Log to stdout so we get timestamps on the logs
     )
 
     if returncode == 0:

ml-agents/tests/yamato/yamato_utils.py

     output_path: str = None,
     scene_path: str = None,
     build_target: str = None,
-    log_output_path: str = f"{get_base_output_path()}/standalone_build.txt",
+    log_output_path: Optional[str] = f"{get_base_output_path()}/standalone_build.txt",
 ) -> int:
     """
     Run BuildStandalonePlayerOSX test to produce a player. The location defaults to
         "Unity.MLAgents.StandaloneBuildTest.BuildStandalonePlayerOSX",
     ]
 
-    os.makedirs(os.path.dirname(log_output_path), exist_ok=True)
-    subprocess.run(["touch", log_output_path])
-    test_args += ["-logfile", log_output_path]
+    if log_output_path:
+        os.makedirs(os.path.dirname(log_output_path), exist_ok=True)
+        subprocess.run(["touch", log_output_path])
+        test_args += ["-logfile", log_output_path]
+    else:
+        # Log to stdout
+        test_args += ["-logfile", "-"]
 
     if output_path is not None:
         output_path = os.path.join(get_base_output_path(), output_path)
 
     # Print if we fail or want verbosity.
     if verbose or res.returncode != 0:
-        subprocess.run(["cat", log_output_path])
+        if log_output_path:
+            subprocess.run(["cat", log_output_path])
 
     return res.returncode