HOTFIX Fix missing FITIO export.

CMakeLists.txt

@@ -133,9 +133,13 @@ target_link_libraries(Pylene INTERFACE Pylene::Core)
 include(GNUInstallDirs)
 
 set(PyleneTargets Pylene Pylene-core Pylene-bp Pylene-io-freeimage)
-if (TARGET Pylene-numpy)
-  list(APPEND PyleneTargets Pylene-numpy)
-endif()
+set(OptionalPyleneTargets Pylene-io-fits Pylene-numpy)
+
+foreach(tgt ${OptionalPyleneTargets})
+  if (TARGET ${tgt})
+    list(APPEND PyleneTargets ${tgt})
+  endif()
+endforeach()
 
 install(TARGETS ${PyleneTargets}
         EXPORT PyleneTargets)