evaluate HDF5 File locking override

it is possible to globally override HDF5's default file locking behaviour

https://support.hdfgroup.org/documentation/hdf5/latest/_file_lock.html

it appears that this is only set by Environment, not on individual files or within constrained scopes.

this may help with Luster MDS load, but managing risks is complicated

initially we should evaluate whether it can significantly help, but caution on adoption paths and risk mitigation is essential, especially in multi-executable environments.