Merge pull request #26177 from nextcloud/backport/26161/stable21

apps/user_ldap/lib/User_LDAP.php

apps/user_ldap/lib/User_Proxy.php

core/Migrations/Version21000Date20210309185127.php

lib/composer/composer/autoload_classmap.php

lib/composer/composer/autoload_static.php

lib/private/Collaboration/Collaborators/UserPlugin.php

lib/private/DB/QueryBuilder/QueryBuilder.php

lib/private/User/Backend.php

lib/private/User/Database.php

lib/private/User/Manager.php

lib/public/DB/QueryBuilder/IQueryBuilder.php

lib/public/IUserManager.php

lib/public/User/Backend/IGetRealUIDBackend.php

lib/public/User/Backend/ISearchKnownUsersBackend.php

lib/public/UserInterface.php

tests/lib/Collaboration/Collaborators/UserPluginTest.php