dep: update a whole bunch of things

[ckipp01]

This pr updates the following:

• various dependencies to the latest
• adds in dependabot
• updates java and checkout actions
• updates ammonite scripts and uses new ammonite in CI
• updates mill to the latest 0.10.5
• bumps scalajs to 1.x
• corrects repo location in pomSettings

[ckipp01]

NOTE: I didn't add in cross testing for 17 since there are actual issues there that would need to be addressed. So that should probably be a follow-up.