remove `geom_col` argument in `element_as_gdf()`?

[jGaboardi]

#720 introduced a small ruff regression where the geom_col keyword is no longer used in util._arcs_as_gdf(), which triggers a ruff failure in pre-commit.

The thought here is that maybe we should remove the geom_col argument in element_as_gdf()? And always default to "geometry".

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EDIT

• deprecated in #724
• remove in v1.8.0

[martinfleis]

Can you think of a use case when you want the column to be called differently and it couldn't be done via an intermediate rename_geometry call?

[jGaboardi]

Nope, I can't think of anything. Let's nix it.