This fixes a cmake warning that the output path does not match
The Q3DViewerModule target is a QML module with target path Q3DViewer. It
uses an OUTPUT_DIRECTORY of
$HOME/dev/qt/dev/src/qtdoc/examples/demos/documentviewer/build/Qt_6_10_0_build-Debug/plugins/q3dviewer,
which should end in the same target path, but doesn't. Tooling such as
qmllint may not work correctly.
Pick-to: 6.9
Change-Id: I33e402a52e3ee5747da428b9a74121e35345f63d
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>