fix: don't create native messaging manifest file unless browser directory exists (#6116)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

tests/CMakeLists.txt

@@ -54,6 +54,7 @@ set(test_SOURCES
     ${CMAKE_CURRENT_LIST_DIR}/src/OnceFlag.cpp
     ${CMAKE_CURRENT_LIST_DIR}/src/IncognitoBrowser.cpp
     ${CMAKE_CURRENT_LIST_DIR}/src/EventSubMessages.cpp
+    ${CMAKE_CURRENT_LIST_DIR}/src/NativeMessaging.cpp
 
     ${CMAKE_CURRENT_LIST_DIR}/src/lib/Snapshot.cpp
     ${CMAKE_CURRENT_LIST_DIR}/src/lib/Snapshot.hpp