Release `r20230210` has changed the model name (missing `ms_`)

[joshuacwnewton]

Between the last release and this new draft release, the name of the model was subtly changed from model_seg_ms_lesion_mp2rage to model_seg_lesion_mp2rage.

Before:

After:

This means that, on SCT's end, we need to change the name of the existing entry for model_seg_ms_lesion_mp2rage, since it no longer matches the model name:

https://github.com/spinalcordtoolbox/spinalcordtoolbox/blob/aef83eb1482ea9360065ac8d8913aaf18edd4ce8/spinalcordtoolbox/deepseg/models.py#L90

I can work around this, but ideally we would keep the names consistent between releases.