www/qt6-webengine: fix build on armv7
Restore a patch that was accidentally dropped during the update to
6.9.1.
Fixes: 03b02222d63f08742cf723fd8eeee26465ae3e39
MFH: 2025Q3
Approved by: portmgr (build fix blanket)
(cherry picked from commit 2b9cc5333412eca542d592774ec08def1f58e48e)