Failing precompilation of HDF5_jll (with OpenMPI 4?)

CI currently fails when precompiling HDF5_jll

Failed to precompile HDF5_jll [0234f1f7-429e-5d53-9886-15a909be8d59] to "/home/runner/.julia/compiled/v1.10/HDF5_jll/jl_CgDWlD".
ERROR: LoadError: InitError: could not load library "/home/runner/.julia/artifacts/689e8d7a066e74f34108119415bd9e46a2f8b168/lib/libmpi_mpifh.so"
/home/runner/.julia/artifacts/689e8d7a066e74f34108119415bd9e46a2f8b168/lib/libmpi_mpifh.so: undefined symbol: ompi_instance_count

This was caused by the recent changes in OpenMPI_jll (https://github.com/JuliaPackaging/Yggdrasil/commit/e449cb642cb89b3ce92e618a1c83c05bdf27c932), which declared the libmpi_mpifh library to be provided by OpenMPI_jll.

The actual cause however is precisely described here: https://github.com/JuliaPackaging/Yggdrasil/issues/6893
We switch to system MPI, and also system HDF5, but HDF5_jll still gets pulled in and will instead load the MPI libraries provided by OpenMPI_jll. In particular it loads OpenMPI_jll's libmpi_mpifh.so, and cannot resolve the ompi_instance_count symbol (which comes with OpenMPI 5?).

Workarounds so far:

• Override the provided libmpi_mpifh.so library in LocalPreferences.toml

  [OpenMPI_jll]
  libmpi_mpifh_path = "/lib/x86_64-linux-gnu/libmpi_mpifh.so"
  

• Downgrade OpenMPI_jll to v4

@KerstinHartung

Start by reproducing the CI precompilation failure for HDF5_jll and inspect how HDF5_jll loads OpenMPI_jll's libmpi_mpifh.so. Compare that behavior with the system MPI and HDF5 setup described in the issue, including the LocalPreferences.toml workaround. Done means CI precompiles HDF5_jll without the undefined ompi_instance_count symbol.