Specify framework in VS Code publish task

[ejizba]

Issue describing the changes in this PR

I use the VS Code publish task when I work on core tools and it's currently giving this error:

The 'Publish' target is not supported without specifying a target framework. The current project targets multiple frameworks, you must specify one of the following frameworks in order to publish: net6.0, net8.0

So I added config that allows you to pick the framework when running the task.

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes do not need to be backported to a previous version
  • Otherwise: Backport tracked by issue/PR #issue_or_pr
• I have added all required tests (Unit tests, E2E tests)