Try to fix libatomic linkage on raspbian

src/libslic3r/CMakeLists.txt

@@ -262,6 +262,12 @@ target_link_libraries(libslic3r
     ${CMAKE_DL_LIBS}
     )
 
+
+find_library(CXX_ATOMIC_LIBRARY atomic)
+if (CXX_ATOMIC_LIBRARY)
+    target_link_libraries(libslic3r ${CXX_ATOMIC_LIBRARY})
+endif()
+
 if (TARGET OpenVDB::openvdb)
     target_link_libraries(libslic3r OpenVDB::openvdb)
 endif()