Fix HDF5 config-mode detection to use shared library when static is absent

When HDF5 is found via its CMake config file, the code previously hardcoded
the hdf5_cpp-static target. On distributions that ship only shared HDF5
(e.g. Fedora rawhide where the config file was added in a newer package),
this caused a link failure. Now checks for hdf5_cpp-static, hdf5_cpp-shared,
and hdf5::hdf5_cpp-shared in order, falling back to module-mode discovery.

cmake/FindHDF5.cmake

@@ -88,7 +88,15 @@ if(NOT HDF5_INCLUDE_DIR OR NOT HDF5_LIBRARY_DIR)
     mark_as_advanced(HDF5_DIR)
     if(HDF5_DIR)
         message(STATUS "HDF5: found config at '${HDF5_DIR}'.")
-        set(HDF5_LIBRARIES hdf5_cpp-static)
+        if(TARGET hdf5_cpp-static)
+            set(HDF5_LIBRARIES hdf5_cpp-static)
+        elseif(TARGET hdf5_cpp-shared)
+            set(HDF5_LIBRARIES hdf5_cpp-shared)
+        elseif(TARGET hdf5::hdf5_cpp-shared)
+            set(HDF5_LIBRARIES hdf5::hdf5_cpp-shared)
+        else()
+            find_package(HDF5 REQUIRED COMPONENTS CXX)
+        endif()
     else()
         # If it failed, still try to find as a module.
         # E.g. on Ubuntu `libhdf5-dev` doesn't provie hdf5-config.cmake.