Tile API should not return tiles if time_slice is outside dataset bounds

## What's happening
Right now if a URL like the following https://prod-titiler-xarray.delta-backend.com/tiles/WebMercatorQuad/1/1/1@1x?url=s3://veda-data-store-staging/Fcmip6-GISS-E2-1-G-tas-kerchunk/Fcombined_CMIP6_daily_GISS-E2-1-G_tas_kerchunk.json&time_slice=2023-09-06T07:00:00.000Z&reference=true&resampling_method=bilinear&variable=tas&colormap_name=coolwarm&rescale=232,312 returns tiles even though the dataset ends in 2014.

## Expected behavior
If the time_slice parameter value does not fit in the dataset's temporal extent, the API should return 204 (this is what titiler-cmr does)