Switched cgroupspy to vendored version (apache#22209)

This is part of the effort needed to implement Python 3.10
compatibility: apache#22050

airflow/task/task_runner/cgroup_task_runner.py

@@ -23,8 +23,8 @@
 import uuid
 
 import psutil
-from cgroupspy import trees
 
+from airflow._vendor.cgroupspy import trees
 from airflow.task.task_runner.base_task_runner import BaseTaskRunner
 from airflow.utils.operator_resources import Resources
 from airflow.utils.platform import getuser

setup.py

@@ -238,8 +238,13 @@ def write_version(filename: str = os.path.join(*[my_dir, "airflow", "git_version
     'celery>=5.2.3',
     'flower>=1.0.0',
 ]
-cgroups = [
-    'cgroupspy>=0.1.4',
+cgroups = [  # type:ignore
+    # Cgroups are now vendored in `airflow/_vendor/cgroupspy` for Python 3.10 compatibility
+    # The vendored code can be removed once cgroupspy released a new version after fixing
+    # the incompatibility https://github.com/cloudsigma/cgroupspy/issues/13 (hopefully >0.2.1 will
+    # be good for that. We should also be able to remove type:ignore above, as MyPy can't derive the type
+    # when this line is commented out
+    # 'cgroupspy>0.2.1',
 ]
 cloudant = [
     'cloudant>=2.0',