Net 9 Migration

[Martin-Molinero]

Expected Behavior

• Migrate to Net 8 which is long term support: all repos, images

  Actual Behavior

• Using Net 6

  Potential Solution

  N/A

  Reproducing the Problem

  N/A

  System Information

  N/A

  Checklist

• [x] I have completely filled out this template
• [x] I have confirmed that this issue exists on the current master branch
• [x] I have confirmed that this is not a duplicate issue by searching issues
• [x] I have provided detailed steps to reproduce the issue

[AlexCatarino]

We might want to do this with the Python upgrade.
https://devguide.python.org/versions/ pythonnet supports 3.12, so can LEAN.

[Martin-Molinero]

Net 9 is released