Unused header file: lalsimulation/lib/LALSimIMRSpinEOBHcapNumericalDerivativePrec.h

The header file LALSimIMRSpinEOBHcapNumericalDerivativePrec.h included in /lalsimulation/lib/ is unused (not referenced in any C source file or Makefile.am build file).

@sebastian-khan @maria.haney, @riccardo-sturani, @harald.pfeiffer, can it be removed?