Feature request: Option to remove geometry in `tile-join`

[indus]

Background

I'm working on a client-side tile merging approach that combines static geometry with geometry-less attribute tilesets: maplibre-merge-protocol

I already use tile-join to prepare the tiles, but currently need a custom step to strip geometry from the original tiles.

Would you accept a PR adding an option to tile-join to remove geometry from features while preserving IDs and attributes?

I understand this would technically produce invalid MVT, but it would be an explicit opt-in option for this advanced workflows where geometry is provided separately and merged client-side.

I'd be happy to try to contribute the PR if this is acceptable.

[e-n-f]

I suppose I would! It's weird to have tiled features without geometry, but if there is a use case and it fits in reasonably well with the rest of the code, it doesn't seem like that bad of an idea.