/usr/include/KF5/KSieveUi/ is in libkf5ksieve-dev 4:17.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/KF5/KSieveUi/AbstractMoveImapFolderWidget
/usr/include/KF5/KSieveUi/AbstractRegexpEditorLineEdit
/usr/include/KF5/KSieveUi/CheckScriptJob
/usr/include/KF5/KSieveUi/ManageSieveScriptsDialog
/usr/include/KF5/KSieveUi/ManageSieveTreeView
/usr/include/KF5/KSieveUi/ManageSieveWidget
/usr/include/KF5/KSieveUi/MultiImapVacationDialog
/usr/include/KF5/KSieveUi/MultiImapVacationManager
/usr/include/KF5/KSieveUi/RenameScriptJob
/usr/include/KF5/KSieveUi/SieveDebugDialog
/usr/include/KF5/KSieveUi/SieveEditor
/usr/include/KF5/KSieveUi/SieveEditorWidget
/usr/include/KF5/KSieveUi/SieveImapAccountSettings
/usr/include/KF5/KSieveUi/SieveImapInstance
/usr/include/KF5/KSieveUi/SieveImapInstanceInterface
/usr/include/KF5/KSieveUi/SieveImapInstanceInterfaceManager
/usr/include/KF5/KSieveUi/SieveImapPasswordProvider
/usr/include/KF5/KSieveUi/SieveTreeWidgetItem
/usr/include/KF5/KSieveUi/Util
/usr/include/KF5/KSieveUi/VacationManager