Add h5py as a real dependency

[stan-dot]

 src/dodal/beamlines/i18.py:17: in <module>
    from dodal.devices.i18.sim_detector import SimDetector
/opt/hostedtoolcache/Python/3.10.14/x64/lib/python3.10/site-packages/dodal/devices/i18/sim_detector.py:2: in <module>
    from ophyd_async.sim import PatternGenerator
/opt/hostedtoolcache/Python/3.10.14/x64/lib/python3.10/site-packages/ophyd_async/sim/__init__.py:1: in <module>
    from .pattern_generator import PatternGenerator
/opt/hostedtoolcache/Python/3.10.14/x64/lib/python3.10/site-packages/ophyd_async/sim/pattern_generator.py:14: in <module>
    import h5py
E   ModuleNotFoundError: No module named 'h5py'
____________ ERROR collecting src/dodal/devices/i18/sim_detector.py ____________
ImportError while importing test module '/home/runner/work/dodal/dodal/src/dodal/devices/i18/sim_detector.py'.

that is because in ophyd-async h5py was added only as a dev dependency

Originally posted by @stan-dot in DiamondLightSource/dodal#722 (comment)

[stan-dot]

spoke with @abbiemery about this , will try to fix fast