Bug: the site_model script is producing duplicated sites

[CatalinaYepes]

The site model generated using the scr/3_2_oq_vs30_uniform_grid.ipynb is producing duplicated sites. Below a configuration example to replicate the issue:

# Events list from ECD
event = 'DRAFT_20230817_M6.1_ElCalvario'

# Reference rupture
rupture = 'earthquake_rupture_model_USGS.xml'

# Grid parameters in km
# Indicate tuples with: (x_distance, y_distance, grid_spacing)
corners = [(100, 100, 5), (250, 250, 10)]

# Define region CRS !!! (CRS UNITS MUST BE IN METERS)
# Check for reference (see https://spatialreference.org/)
region_crs = "EPSG:3857"  # EPSG:3857 - Web Mercator Auxiliary Sphere

# Clip sites based on country boundaries (use ISO3)
clip_countries = ['COL'] # Empty list for the full map

The error message is:

...

openquake.baselib.InvalidFile: Found duplicate sites {(-72.61278, 3.52155): 2, (-72.61278, 3.61121): 2, (-72.61278, 3.70086): 2, (-72.61278, 3.79049): 2, (-72.61278, 3.88013): 2, (-72.61278, 3.96975): 2, (-72.61278, 4.05936): 2, (-72.61278, 4.14896): 2, (-72.61278, 4.23855): 2, (-72.61278, 4.32813): 2, (-72.61278, 4.4177): 2, (-72.61278, 4.50726): 2, (-72.61278, 4.59681): 2, (-72.61278, 4.68634): 2, (-72.61278, 4.77587): 2, (-72.61278, 4.86538): 2, (-72.61278, 4.95489): 2, (-72.61278, 5.04438): 2, (-72.61278, 5.13385): 2, (-72.61278, 5.22332): 2, (-72.61278, 5.31277): 2} in /earthquake-scenarios/Colombia/20230817_M6.1_ElCalvario/OpenQuake_gmfs/site_model.csv