fix: [build] Add minimum Qt5 version requirement check

Add explicit version check to ensure Qt5 version is at least 5.15 when building
with Qt5 interface. This prevents build failures with older Qt5 versions that
may lack required features.

The check is added right after finding Qt5Concurrent package and will fail
with a clear error message if an incompatible version is detected.

CMakeLists.txt

@@ -161,6 +161,12 @@ ELSEIF("${INTERFACE_TYPE}" STREQUAL "qt5" OR "${INTERFACE_TYPE}" STREQUAL "qt6")
 
     SET(CMAKE_AUTOMOC ON)
     FIND_PACKAGE(Qt${QT_VER}Concurrent REQUIRED)
+    IF(${QT_VER} STREQUAL "5")
+        IF(Qt5Concurrent_VERSION VERSION_LESS 5.15)
+	    MESSAGE(FATAL_ERROR "Qt5 version must be at least 5.15 (found ${Qt5Concurrent_VERSION})")
+	ENDIF()
+    ENDIF()
+
     FIND_PACKAGE(Qt${QT_VER}DBus REQUIRED)
     FIND_PACKAGE(Qt${QT_VER}Network REQUIRED)
     FIND_PACKAGE(Qt${QT_VER}Widgets REQUIRED)