qt5_make_output_file creates bad paths

The qt5_make_output_file routine joins paths together improperly on Windows (seems similar to https://bugreports.qt.io/browse/QTBUG-81715 but this patch is applied so it cannot be the same bug.

Here is the call to add the resources

qt5_add_resources(RESOURCES ${CMAKE_CURRENT_BINARY_DIR}/../kirigami.qrc )

The paths get joined together improperly by the call Qt5CoreMacros.cmake(61) below. For reference, before expansion:
file(RELATIVE_PATH rel ${CMAKE_CURRENT_SOURCE_DIR} ${infile}).

Trace-Expanded output

D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(256): qt5_make_output_file(C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/kirigami.qrc qrc.depends out_depends )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(51): _qt5_warn_deprecated(qt5_make_output_file )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(43): if(NOT DEFINED _QT5_INTERNAL_SCOPE )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(53): string(LENGTH C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/src _binlength )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(54): string(LENGTH C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/kirigami.qrc _infileLength )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(55): set(_checkinfile D:/myapp/Kirigami/src/kirigami/src )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(56): if(_infileLength GREATER _binlength )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(57): string(SUBSTRING C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/kirigami.qrc 0 73 _checkinfile )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(58): if(_checkinfile STREQUAL C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/src )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(60): else()
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(61): file(RELATIVE_PATH rel D:/myapp/Kirigami/src/kirigami/src C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/kirigami.qrc )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(66): if(WIN32 AND rel MATCHES ^([a-zA-Z]).*)$ )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(69): set(_outfile C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/src/C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/kirigami.qrc )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(70): string(REPLACE .. __ _outfile C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/src/C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/kirigami.qrc )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(71): get_filename_component(outpath C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/src/C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/kirigami.qrc PATH )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(72): if(CMAKE_VERSION VERSION_LESS 3.14 )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(77): else()
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(78): get_filename_component(_outfile C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/src/C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/kirigami.qrc NAME_WLE )
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake(80): file(MAKE_DIRECTORY C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/src/C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami )
CMake Error at D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake:80 (file):
file problem creating directory:
C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami/src/C:/Users/mtmcp/Documents/LibKirigami/Debug/android/x86/build/kirigami
Call Stack (most recent call first):
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake:256 (qt5_make_output_file)
D:/Qt_Pro/5.15.0/android/lib/cmake/Qt5Core/Qt5CoreMacros.cmake:339 (_qt5_parse_qrc_file)
src/CMakeLists.txt:65 (qt5_add_resources)