Remove fires with no stations

related to #81 (closed)

This fire has no stations in the stations.csv file, but the command completed successfully with no errors

poetry run flowalert debrisflow add tex2024 -c "//data/rainfall_web/flowalert2/.flowalert/config.ini"
INFO:root:Downloading shapefiles url https://landslides.usgs.gov/static/landslides-realtime/fires/tex2024/Shapefiles.zip
Added fire tex2024 to //data/rainfall_web/flowalert2/.flowalert/config.ini

I think what is happening is rainfall stations are found within the bounding box of the fire, but are filtered out by this function https://code.usgs.gov/ghsc/lhp/FlowAlert/-/blob/release/src/flowalert/debrisflow.py#L60-L83

Acceptable criteria

• confirm the cause of this issue
• if all stations are filtered out, delete the fire from the config, and delete the fire directory
• return useful error message like no stations found within {buffer_m} of the {fire_id} fire perimeter, aborting