6.9.0 regression: Qt6TestTargets.cmake change causes OpenCV build failure

Trying to build OpenCV 4.11.0 after updating to Qt 6.9.0-RC results in a build failure. When using cmake -G Ninja, it happens during the cmake run:
ninja: error: build.ninja:28048: bad $-escape (literal $ must be written as $$)
When using cmake -G "Unix Makefiles", the cmake run succeeds, but make fails later when running into a syntax error in the Makefiles.

The cause is the new INTERFACE_COMPILE_DEFINITIONS for Qt6::Test (Qt6TestTargets.cmake line 72).

Commenting out the whole line:
INTERFACE_COMPILE_DEFINITIONS "QT_TESTLIB_LIB;QT_TESTCASE_BUILDDIR=\"\$<IF:\$<BOOL:\$<TARGET_PROPERTY:QT_TESTCASE_BUILDDIR>>,\$<TARGET_PROPERTY:QT_TESTCASE_BUILDDIR>,\$<TARGET_PROPERTY:BINARY_DIR>>\";QT_TESTCASE_SOURCEDIR=\"\$<TARGET_PROPERTY:SOURCE_DIR>\""
"fixes" the problem.