Add destroy units

[cderici]

Description

This brings back the separate model.destroy_units(*units) as a quality of life feature.

Fixes #811

QA Steps

All the regular tests should pass. Additionally, this also adds a separate integration test for destroy_units, so the following should be passing (I tried it on juju 3.1).

tox -e integration -- tests/integration/test_model.py::test_destroy_units

Notes & Discussion

As a future reference, this was changed in #791.

[addyess]

you can do this or this:

Suggested change

	for u in unit_names:
	await self.destroy_unit(u, destroy_storage, dry_run, force, max_wait)
	await jasyncio.gather(*(
	self.destroy_unit(u, destroy_storage, dry_run, force, max_wait)
	for u in unit_names
	))

While I believe your proposed solution here would get the job done, it may be quicker to not issue the Destroy sequentially. I don't know how long it actually takes to actually start one destroy_unit

[cderici]

Unless it makes things significantly slower, I'd prefer to depend on asyncio as little as possible as we ultimately want to get rid of it. I didn't observe such performance deficit when I was running the tests, but feel free to run a comparison on it if you're curious 👍

[addyess]

nope it's totally your call here! thanks for the PR. LGTM

[juanmanuel-tirado]

Test unit annotations is failing
[gw0] [ 85%] FAILED tests/integration/test_model.py::test_unit_annotations

[juanmanuel-tirado]

LG2M

[cderici]

That failing test FAILED tests/integration/test_controller.py::test_secrets_backend_lifecycle (failing with ConnectionRefusedError: [Errno 111] Connection refused) is a known problem that's unrelated to this PR. @juanmanuel-tirado We should address that separately in another one.

[cderici]

/merge