Update HDF5 version to 2.0.0-4 after snapshot release 2.0.0-3

[lrknox]

Increment subversion to -4.

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Important

Update HDF5 version from 2.0.0-3 to 2.0.0-4 across multiple files without additional changes.

• Version Update:
  • Increment HDF5 version from 2.0.0-3 to 2.0.0-4 in README.md, HDF5config.cmake, HDF5AsSubdirMacros.cmake, CHANGELOG.md, and H5public.h.
• Misc:
  • No additional functionality changes or bug fixes included in this update.

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