Unpin astropy in MIRI YSO notebook when aplpy is released with fix

### Notebook Name:

IFU of YSOs in LMC

### Description

This notebook requires aplpy and this package breaks with astropy=6.0.0.
Astropy is currently pinned to 5.3.2 so the notebook can run, but it will need to be unpinned as soon as aplpy has a new release with a fix.