Allow mounting volume for outputs

[elliotgunton]

• Still use /tmp for script outputs but allow mounting own volume with volume_for_outputs passed to Runner constructor
• Fix examples using volumes incorrectly and simplify where possible

[codecov]

Codecov Report

Merging #780 (c5a42e5) into main (bb3c7c0) will increase coverage by 0.0%.
Report is 1 commits behind head on main.
The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main    #780   +/-   ##
=====================================
  Coverage   78.2%   78.3%           
=====================================
  Files         45      45           
  Lines       3639    3643    +4     
  Branches     732     734    +2     
=====================================
+ Hits        2847    2853    +6     
+ Misses       594     593    -1     
+ Partials     198     197    -1     

Files	Coverage Δ
src/hera/workflows/_mixins.py	79.6% <100.0%> (ø)
src/hera/workflows/runner.py	79.7% <ø> (ø)
src/hera/workflows/script.py	86.1% <100.0%> (+0.7%)	⬆️

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[dejamiko]

This return object looks strange to me.

It has a given name and the from_ has the same name in the path? We don't return the Artifact but rather create a new one with a populated from_ string. At a glance, it is unclear why this doesn't return the old Artifact object but creates a new one with a reference.

If we are doing that, for clarity, we might want to change the function slightly to combine the get_artifact with as_name and use the provided "new name" for the return object. We can make the new_name equal to old_name for convenience but I feel like this would be clearer to the user.

[elliotgunton]

I agree it looks strange, but it makes a bit more sense from the user's perpective e.g. for parameters we have with_name which kind of matches our new callable syntax, and is used like:

t1 = Task(name="a", template=out)
t2 = Task(name="b", template=in_, arguments=t1.get_parameter("x").with_name("a"))

And for artifacts we have as_name (which we should probably deprecate and use with_name as well):

out = output_artifact(arguments={"a_number": 3})
use_artifact(arguments=[out.get_artifact("successor_out").as_name("successor_in")])

Your suggestion would be a small change to e.g.

out = output_artifact(arguments={"a_number": 3})
use_artifact(arguments=[out.get_artifact("successor_out", with_name="successor_in")])

Which I'm open to, but I'd rather nail that change down in the new callable syntax PR, this line change was just to remove the path which isn't used for artifacts-as-arguments.