Removal for Rhino8 flag in compas 2.9.0 too soon

Hi, we have been using COMPAS with the MAS ETH DFAB students in Rhino 8 but with the (now) legacy `python -m compas_rhino.install`. Our workflow was more or less same as `Rhino7 ` - using the `IronPython` ScriptEditor in Grasshopper (we do not use the GH components). This works quite well (maybe only in our narrow world-view), as we could have conda environments for students where they can have multiple dependencies, and then choose to work in _or_ outside Rhino.

Now, assuming `Python3` component is the future for `Rhino8` and `COMPAS` - the only way to replicate the workflow would be to have parallel `conda` and Rhino `venvs` to do this; which might be fine, but in my experience the Python3 component is semi-stable at best; so it feels a bit unnecessary to remove support for `Python2.7` already. For now, we could stay in the past by using either `compas 2.8.1` or `Rhino7`; but would be cool to understand how these workflows are envisioned in the long-run.

I have discussed this with @gonzalocasas briefly and he suggested with @chenkasirer @tomvanmele we could discuss this here. What do you guys think?