move fmt handling into prereqs hook

CMakeLists.txt

@@ -49,6 +49,10 @@ macro(opm-simulators_prereqs_hook)
     set(HDF5_FOUND OFF)
     unset(HAVE_HDF5)
   endif()
+
+  if(NOT fmt_FOUND)
+    include(DownloadFmt)
+  endif()
 endmacro()
 
 macro(opm-simulators_sources_hook)
@@ -111,9 +115,6 @@ macro(opm-simulators_config_hook)
       opm_need_version_of ("dune-fem")
   endif()
 
-  if(NOT fmt_FOUND)
-    include(DownloadFmt)
-  endif()
   if(USE_TRACY_PROFILER AND Tracy_FOUND)
     set(USE_TRACY 1)
     list(APPEND opm-simulators_LIBRARIES Tracy::TracyClient)

opm-simulators-prereqs.cmake

@@ -68,6 +68,7 @@ set (opm-simulators_DEPS
   "Damaris 1.9"
   "HDF5"
   "Tracy"
+  "fmt"
   )
 
 find_package_deps(opm-simulators)