make zip step more efficient/ robust

[ksonda]

from slack:

Kyle Onda 4:09 PM
this messed up the pid workflow https://github.com/papeloto/action-zip/issues (edited)

Ben Webb 4:12 PM
hm

Kyle Onda 4:12 PM
i just changed to the new name
4:12
but that is sooo dumb and important to us we should probably host our own action

Ben Webb 4:14 PM
i recall using zip -r backup/sitemap.zip yourls/sitemap
New
4:18
but also we only have that because every time the sitemap is generated it updates the timestamps for every single PID which is a lot …. there is probably a better way to go about that