No such file or directory: 'lsof': 'lsof'

This is breaking the nightlies

af7cd135

Check it out.

https://gitlab.idiap.ch/bob/bob.nightlies/-/jobs/162026

    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/bob/devtools/scripts/bdt.py", line 42, in _decorator
    value = view_func(*args, **kwargs)
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/bob/devtools/scripts/ci.py", line 512, in nightlies
    current_open_files = open_files()
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/bob/devtools/log.py", line 245, in open_files
    procs = subprocess.check_output(['lsof', '-w', '-p', str(pid)])
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/subprocess.py", line 389, in check_output
    **kwargs).stdout
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/subprocess.py", line 466, in run
    with Popen(*popenargs, **kwargs) as process:
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/subprocess.py", line 769, in __init__
    restore_signals, start_new_session)
  File "/scratch/builds/bob/bob.nightlies/miniconda/lib/python3.7/subprocess.py", line 1516, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'lsof': 'lsof'

This is weird. This is supposed to be a linux standard command, no?