Decl'HDF5 fails to load on OSX

[jbigot]

As demonstrated in https://github.com/pdidev/pdi/actions/runs/17427413281/job/49477602600?pr=576 loading the Decl'HDF5 plugin leads to an assertion:

Assertion failed: ((char *)dest >= (const char *)src + n || (const char *)src >= (char *)dest + n), function H5MM_memcpy, file H5MM.c, line 613.

@tpadioleau wonders whether this is related to https://nvd.nist.gov/vuln/detail/CVE-2021-36977

I guess we do something at initialization that is not completely valid. We'd need to investigate that specifically and get a stacktrace.