generalise handling of szip(.dll)?.a in other builds

It was set up to work when szip is unpacked from a previous build,
in whuch case the libsz.a file existed.  But this renaming is done
in the packing step so new builds have libsz.dll.a.

The need to specify the libsz path might ultimately be due to
the pkg-config version but this approach works for now.

Tag to allow release of extlibs built using GCC13.2 UCRT with MCF thr…

…eads

Merge pull request #47 from StrawberryPerl/libgd-2.3.2

Update 5034 build file to use libgd-2.3.2

update netcdf to 4.9.2 (#45)

The patch file is not really needed as it
is for cmake.

build.sh: use default dllsuffix when args are package names