Fix cmake overidding CMAKE_PREFIX_PATH (#873)

Author: pifopi

SerialPrograms/CMakeLists.txt

@@ -87,7 +87,7 @@ if(WIN32 AND QT_DEPLOY_FILES)
     set(QT_BASE_DIR "C:/Qt")
     if(QT_CANDIDATE_DIR AND EXISTS "${QT_CANDIDATE_DIR}")
         message(STATUS "Using preferred Qt directory for Qt${QT_MAJOR} ${PREFERRED_QT_VER}: ${QT_CANDIDATE_DIR}")
-        set(CMAKE_PREFIX_PATH "${QT_CANDIDATE_DIR}")
+        list(APPEND CMAKE_PREFIX_PATH "${QT_CANDIDATE_DIR}")
         find_package(Qt${QT_MAJOR} ${PREFERRED_QT_VER} COMPONENTS Widgets SerialPort Multimedia MultimediaWidgets REQUIRED)
     else()
         # Find all subdirectories in the Qt base directory
@@ -104,7 +104,7 @@ if(WIN32 AND QT_DEPLOY_FILES)
         # Debug message to verify the latest Qt directory
         if(QT_LATEST_DIR)
             message(STATUS "Latest Qt directory for Qt${QT_MAJOR}: ${QT_LATEST_DIR}")
-            set(CMAKE_PREFIX_PATH "${QT_LATEST_DIR}/msvc2022_64/lib/cmake")
+            list(APPEND CMAKE_PREFIX_PATH "${QT_LATEST_DIR}/msvc2022_64/lib/cmake")
         else()
             message(FATAL_ERROR "No Qt${QT_MAJOR} installation found in ${QT_BASE_DIR}")
         endif()