Support float32 inputs

[hombit]

Function like lonlat_to_healpix doesn't support float32 inputs for coordinates. Could you please add support of that?

import cdshealpix
from astropy.coordinates import Latitude, Longitude

cdshealpix.lonlat_to_healpix(
     lon=Longitude(np.array(3, dtype=np.float32), 'deg'),
     lat=Latitude(np.array(5,dtype=np.float32), 'deg'),
     depth=2
)

File ~/.virtualenvs/v/lib/python3.12/site-packages/cdshealpix/utils.py:47, in _validate_lonlat.<locals>._validate_lonlat_wrap(lon, lat, *args, **kwargs)
     45 lon = lon if isinstance(lon, Longitude) else Longitude(lon)
     46 lat = lat if isinstance(lat, Latitude) else Latitude(lat)
---> 47 return function(lon, lat, *args, **kwargs)

File ~/.virtualenvs/v/lib/python3.12/site-packages/cdshealpix/nested/healpix.py:101, in lonlat_to_healpix(lon, lat, depth, return_offsets, num_threads)
     99 depth = depth.astype(np.uint8)
    100 num_threads = np.uint16(num_threads)
--> 101 cdshealpix.lonlat_to_healpix(depth, lon, lat, ipix, dx, dy, num_threads)
    103 if return_offsets:
    104     return ipix, dx, dy

TypeError: argument 'lon': 'ndarray' object cannot be converted to 'PyArray<T, D>'

This issue was originally reported by a couple of ZTF-related hats-import pipelines:
astronomy-commons/hats-import#458
astronomy-commons/hats-import#460 (comment)