/usr/share/sip/PyQt4/QtXml/ is in python-qt4-dev 4.11.4+dfsg-1build4.
This file is owned by root:root, with mode 0o755.
..
/usr/share/sip/PyQt4/QtXml/QtXmlmod.sip
/usr/share/sip/PyQt4/QtXml/qdom.sip
/usr/share/sip/PyQt4/QtXml/qxml.sip
/usr/share/sip/PyQt4/QtXml/qxmlstream.sip
/usr/share/sip/PyQt4/QtXmlPatterns/QtXmlPatternsmod.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qabstractmessagehandler.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qabstracturiresolver.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qabstractxmlnodemodel.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qabstractxmlreceiver.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qsimplexmlnodemodel.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qsourcelocation.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qxmlformatter.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qxmlname.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qxmlnamepool.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qxmlquery.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qxmlresultitems.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qxmlschema.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qxmlschemavalidator.sip
/usr/share/sip/PyQt4/QtXmlPatterns/qxmlserializer.sip