1. Fix resource warning in the destructor
```
/Users/REDACTED/.asdf/installs/python/3.10.0/lib/python3.10/subprocess.py:1067: ResourceWarning: subprocess 46612 is still running
_warn("subprocess %s is still running" % self.pid,
ResourceWarning: Enable tracemalloc to get the object allocation traceback
```
2. Use preferred, non-legacy API per https://docs.python.org/3/library/subprocess.html#subprocess.call
3. Older call style no longer needed with Python 3.6+