Move the location to import eups in fiberids.py of pfs_utils

fiberids.py in python/pfs/utils/ in pfs_uitls imports eups at the top section, but it is only used to look up the PFS_UTILS parameter using eups.productDir('PFS_UTILS'). As the constructor of FiberIds allows to be called with a path to the fiberid data directory, it would be nice if the import line is moved right above the line using eups to minimize the dependency to eups for Python environments not using it.

Specifically, I'd like to move the import line to here:

https://github.com/Subaru-PFS/pfs_utils/blob/b922f60fa44dec1a96dfb5739f2c2737486c04ec/python/pfs/utils/fiberids.py#L57