vigra: fix hdf5 discovery

The vigra package currently claims hdf5 not foun
due to szip supporch check HDF5_SZLIB_OK not passing.

Szip support has been added to the hdf5 package
with commit 96e0d84b53 ("hdf5: enable szip with libaec"),
and vigra's FindHDF5.cmake is aware of that by testing with H5pubconf.h.
What fails the HDF5_SZLIB_OK check happens to be szip not presented,
which is not quite sensible as vigra itself doesn't use szip.

Before fixing from the upstream, let's present szip and please the check
Here, libaec is a FOSS implementation of the unfree szip.

pkgs/by-name/vi/vigra/package.nix

@@ -7,6 +7,7 @@
   fftw,
   fftwSinglePrec,
   hdf5,
+  libaec,
   libjpeg,
   libpng,
   libtiff,
@@ -43,6 +44,9 @@ stdenv.mkDerivation (finalAttrs: {
     (hdf5.override {
       apiVersion = "v110";
     })
+    # Satisfy the HDF5_SZLIB_OK check in the source's config/FindHDF5.cmake
+    # libaec is a drop-in replacement of szip.
+    libaec
     libjpeg
     libpng
     libtiff