ebs__download_snapshots fails when computing out_dir.relative_to('.')

[niooss-ledger]

Hello,
I tried downloading an EBS snapshot using Pacu 1.6.0 and got an error after all the data was downloaded:

Pacu (mysession:xxx) > run ebs__download_snapshots --region eu-west-1 --snapshot-id snap-01[[REDACTED]]
  Running module ebs__download_snapshots...
Output Path: /root/.local/share/pacu/mysession/downloads/ebs/snapshots/snap-01[[REDACTED]].img
Truncating file to 8.0 GB
Saved block 16369 of 16369
[2024-07-08 09:40:57] Pacu encountered an error while running the previous command. Check /root/.local/share/pacu/mysession/error_log.txt for technical details. [LOG LEVEL: MINIMAL]

    <class 'ValueError'>: '/root/.local/share/pacu/mysession/downloads/ebs/snapshots' is not in the subpath of '' OR one path is relative and the other is absolute.

The error log file (/root/.local/share/pacu/mysession/error_log.txt) contains this call trace:

[2024-07-08 09:40:57] (mysession): 
Traceback (most recent call last):
  File "/usr/local/lib/python3.11/dist-packages/pacu/main.py", line 1827, in run_gui
    self.idle()
  File "/usr/local/lib/python3.11/dist-packages/pacu/main.py", line 1681, in idle
    self.parse_command(command)
  File "/usr/local/lib/python3.11/dist-packages/pacu/main.py", line 600, in parse_command
    self.parse_exec_module_command(command)
  File "/usr/local/lib/python3.11/dist-packages/pacu/main.py", line 786, in parse_exec_module_command
    self.exec_module(command)
  File "/usr/local/lib/python3.11/dist-packages/pacu/main.py", line 1003, in exec_module
    summary_data = module.main(command[2:], self)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/pacu/modules/ebs__download_snapshots/main.py", line 94, in main
    out_dir=str(out_dir.relative_to('.')),
                ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/pathlib.py", line 731, in relative_to
    raise ValueError("{!r} is not in the subpath of {!r}"
<class 'ValueError'>: '/root/.local/share/pacu/mysession/downloads/ebs/snapshots' is not in the subpath of '' OR one path is relative and the other is absolute.

The issue is that out_dir is not relative to the current directory, in

pacu/pacu/modules/ebs__download_snapshots/main.py

Lines 93 to 98 in 470b96a

	return SummaryData(
	out_dir=str(out_dir.relative_to('.')),
	snapshot_id=snapshot_id,
	snapshot_path=str(snap.path),
	vagrantfile=str(utils.init_vagrant(out_dir, True)),
	)

(In my use-case, out_dir was "/root/.local/share/pacu/mysession/downloads/ebs/snapshots/").

The call to .relative_to('.') was added in commit e5c3f36 ("ebs__download_snapshots fixes and improvements") from PR #232 and it seems that at the time, the download directory was ./sessions/$SESSION/downloads/ebs/ instead of ~/.local/share/pacu/.... I believe this call to .relative_to('.') should now be removed. What do you think?