Meta: Add aconv as a Lagom tool

Meta/Lagom/CMakeLists.txt

@@ -489,6 +489,9 @@ if (BUILD_LAGOM)
         add_executable(abench ../../Userland/Utilities/abench.cpp)
         target_link_libraries(abench LibCore LibMain LibFileSystem LibAudio)
 
+        add_executable(aconv ../../Userland/Utilities/aconv.cpp)
+        target_link_libraries(aconv LibCore LibMain LibAudio)
+
         if (NOT EMSCRIPTEN)
             add_executable(adjtime ../../Userland/Utilities/adjtime.cpp)
             target_link_libraries(adjtime LibCore LibMain)