typo in 3 lines

Hi, I found a typo in 3 lines: https://git.ligo.org/lscsoft/bilby/-/blame/master/bilby/gw/source.py#L208 https://git.ligo.org/lscsoft/bilby/-/blame/master/bilby/gw/source.py#L617 https://git.ligo.org/lscsoft/bilby/-/blame/master/bilby/gw/source.py?page=2#L1127

it's not something dangerous, since all of them are just 'print' in case of some errors. typo: spin_1=(spin_1x, spin_**2**y, spin_1z)--> spin_1=(spin_1x, spin_1y, spin_1z)`

Best, Manuel Piarulli