Fix dispose not being invoked

[ramonsmits]

Fix dispose not being invoked and aligned all command runners to use using var

[mauroservienti]

Not sure we want to bring this into the net8 branch. In the primary instance, we drastically changed the way bootstrapping works and got rid of the bootstrapper class.

[ramonsmits]

@mauroservienti I know, that is why I applied it on this branch to not have any merge conflicts that need to be resolved later

[mauroservienti]

@ramonsmits, I lost track of this PR. Do we still need to bring this into the net8 branch?

[ramonsmits]

@mauroservienti I've updated the branch as the problem still exists on master