Async future handling needs a guava friendly way we can maintain.

[drcrallen]

As per #5414 (comment) , we need an abstraction that plays nice with Guava versions across a wide range, and ideally uses Java intrinsics whenever possible.

[leventov]

java.util.concurrent.CompletableFuture alone covers a lot, if not all, cases when Druid uses Guava's ListenableFutures and utilities.

[stale]

This issue has been marked as stale due to 280 days of inactivity. It will be closed in 2 weeks if no further activity occurs. If this issue is still relevant, please simply write any comment. Even if closed, you can still revive the issue at any time or discuss it on the dev@druid.apache.org list. Thank you for your contributions.

[stale]

This issue has been closed due to lack of activity. If you think that is incorrect, or the issue requires additional review, you can revive the issue at any time.

[github-actions]

This issue has been marked as stale due to 280 days of inactivity.
It will be closed in 4 weeks if no further activity occurs. If this issue is still
relevant, please simply write any comment. Even if closed, you can still revive the
issue at any time or discuss it on the dev@druid.apache.org list.
Thank you for your contributions.