always link with libdl.so/.a or equivalent except on windows

cmake/CMakeLists.txt

@@ -240,6 +240,11 @@ if(BUILD_OMP)
   target_link_libraries(lammps PRIVATE OpenMP::OpenMP_CXX)
 endif()
 
+# link with -ldl or equivalent for plugin loading; except on Windows
+if(NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
+  target_link_libraries(lammps PRIVATE ${CMAKE_DL_LIBS})
+endif()
+
 # Compiler specific features for testing
 if(${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU")
   option(ENABLE_COVERAGE "Enable collecting code coverage data" OFF)

cmake/Modules/Packages/USER-MOLFILE.cmake

@@ -2,8 +2,4 @@ set(MOLFILE_INCLUDE_DIR "${LAMMPS_LIB_SOURCE_DIR}/molfile" CACHE STRING "Path to
 set(MOLFILE_INCLUDE_DIRS "${MOLFILE_INCLUDE_DIR}")
 add_library(molfile INTERFACE)
 target_include_directories(molfile INTERFACE ${MOLFILE_INCLUDE_DIRS})
-# no need to link with -ldl on windows
-if(NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
-  target_link_libraries(molfile INTERFACE ${CMAKE_DL_LIBS})
-endif()
 target_link_libraries(lammps PRIVATE molfile)