Spack package implementation with Ascent rebuild pipeline

[cameronrutherford]

Need to make sure that Ascent rebuild can push to GitHub, and then this is good to go! See Spack PR here: spack/spack#40149

[cameronrutherford]

LGTM @pelesh and @ryandanehy I think this is ready

[cameronrutherford]

I still didn't update docs like I said I would, so perhaps we just make another issue so I get back to that... this is basically the same as ExaGO scripts so I would just be re-typing what's mostly in there with a few modifications

[pelesh]

I still didn't update docs like I said I would, so perhaps we just make another issue so I get back to that... this is basically the same as ExaGO scripts so I would just be re-typing what's mostly in there with a few modifications

More documentation would be helpful, especially for Spack related issues, but I agree, we need a first stab at this in the main development branch.

[cameronrutherford]

@ryandanehy feature or bug, the commit that's automated runs all testing again. We can change that by adding [ascent-test], but I would love to find a way to skip GitHub actions with different rules based on strings in commit messages, but am yet to bother. Especially applies with ExaGO and other repos where GitHub actions can be longer running builds.