[stable18] Correctly remove usergroup shares on removing group members

[backportbot-nextcloud]

backport of #22015

[faily-bot]

🤖 beep boop beep 🤖

Here are the logs for the failed build:

Status of 31198: failure

mariadb10.1-php7.2

Show full log

There were 8 warnings:

1) Test\DB\DBSchemaTest::testSchema
Using assertContains() with string haystacks is deprecated and will not be supported in PHPUnit 9. Refactor your test to use assertStringContainsString() or assertStringContainsStringIgnoringCase() instead.

2) OCA\DAV\Tests\unit\CalDAV\CalDavBackendTest::testCalendarQuery with data set "all" (array(0, 1, 2, 3), array(), array())
The optional $canonicalize parameter of assertEquals() is deprecated and will be removed in PHPUnit 9. Refactor your test to use assertEqualsCanonicalizing() instead.

3) OCA\DAV\Tests\unit\CalDAV\CalDavBackendTest::testCalendarQuery with data set "only-todos" (array(), array('VTODO'), array())
The optional $canonicalize parameter of assertEquals() is deprecated and will be removed in PHPUnit 9. Refactor your test to use assertEqualsCanonicalizing() instead.

4) OCA\DAV\Tests\unit\CalDAV\CalDavBackendTest::testCalendarQuery with data set "only-events" (array(0, 1, 2, 3), array(), array(array('VEVENT', false, array(), array(null, null), array())))
The optional $canonicalize parameter of assertEquals() is deprecated and will be removed in PHPUnit 9. Refactor your test to use assertEqualsCanonicalizing() instead.

5) OCA\DAV\Tests\unit\CalDAV\CalDavBackendTest::testCalendarQuery with data set "start" (array(1, 2, 3), array(), array(array('VEVENT', false, array(), array(DateTime Object (...), null), array())))
The optional $canonicalize parameter of assertEquals() is deprecated and will be removed in PHPUnit 9. Refactor your test to use assertEqualsCanonicalizing() instead.

6) OCA\DAV\Tests\unit\CalDAV\CalDavBackendTest::testCalendarQuery with data set "end" (array(0), array(), array(array('VEVENT', false, array(), array(null, DateTime Object (...)), array())))
The optional $canonicalize parameter of assertEquals() is deprecated and will be removed in PHPUnit 9. Refactor your test to use assertEqualsCanonicalizing() instead.

7) OCA\DAV\Tests\unit\CalDAV\CalDavBackendTest::testCalendarQuery with data set "future" (array(3), array(), array(array('VEVENT', false, array(), array(DateTime Object (...), null), array())))
The optional $canonicalize parameter of assertEquals() is deprecated and will be removed in PHPUnit 9. Refactor your test to use assertEqualsCanonicalizing() instead.

8) OCA\FederatedFileSharing\Tests\FederatedShareProviderTest::testCreate
assertArraySubset() is deprecated and will be removed in PHPUnit 9.

--

There was 1 failure:

1) OCA\Files_Sharing\Tests\SharedMountTest::testPermissionMovedGroupShare with data set #210 ('folder', 27, 7)
Failed asserting that false is true.

/drone/src/apps/files_sharing/tests/SharedMountTest.php:361