test(User): register Backend+DB users for proper cleanup

[joshtrichards]

• Resolves: #

Summary

Should help further with some flaky test failures. These users weren't being properly registered via getUser in the test scenarios for cleanup/teardown, leading to leaks between tests.

TODO

• ...

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

[joshtrichards]

/backport to stable32

[provokateurin]

You're just changing the way the usernames are generated, but they are not cleaned up afterwards like you said in the description.
I assume it still helps because the usernames have a unique prefix which should avoid collisions?

[joshtrichards]

@provokateurin Backend's getUser isn't the one used; in the downstream implementations, tracking and cleanup is implemented in their own $this->getUser() implementations/etc.

server/tests/lib/User/DatabaseTest.php

Lines 32 to 35 in f15d811

	public function getUser() {
	$user = parent::getUser();
	$this->users[] = $user;
	return $user;

server/tests/lib/User/DatabaseTest.php

Lines 46 to 54 in f15d811

	protected function tearDown(): void {
	if (!isset($this->users)) {
	return;
	}
	foreach ($this->users as $user) {
	$this->backend->deleteUser($user);
	}
	parent::tearDown();
	}

[provokateurin]

Alright, this wasn't clear from just looking at the diff 👍