Expose `close_on_exec:` option in shared endpoint.

[ioquatix]

Description

Sometimes we want to pre-bind endpoints without inheriting them by child processes.

Types of Changes

• Bug fix.
• New feature.

Testing

• [ ] I added tests for my changes.
• [ ] I tested my changes locally.
• [ ] I tested my changes in staging.
• [ ] I tested my changes in production.