Feature/retire fiona

[allixender]

Retire Fiona as a required dependency and transition to Pyogrio as the default high-performance engine for GeoPandas I/O.
Tasks:

Refactor get_geo_out to check for driver availability via pyogrio instead of fiona.
Explicitly set engine='pyogrio' in all gpd.read_file and gdf.to_file calls.
Validate that GDAL driver names used by pyogrio align with existing logic.
Move fiona to optional dependencies or remove it entirely.
Ensure the has_gdal=False fallback (Shapefiles) still works correctly with Pyogrio.