Tokio Backends

[GeekMasher]

This pull request includes several changes to update dependencies, add new backend support, and modify the server-rocket example to use asynchronous connections. The most important changes include updating versions, adding support for backends-tokio, and refactoring the server-rocket example to use tokio::sync::Mutex.

Version Updates:

• Updated the version of the geekorm package from 0.8.2 to 0.8.3 in .release.yml and Cargo.toml files. [1] [2] [3] [4] [5]

Backend Support:

• Added support for backends-tokio in Cargo.toml files and updated dependencies accordingly. [1] [2] [3]

Server-Rocket Example Refactor:

• Refactored the server-rocket example to use tokio::sync::Mutex for asynchronous database connections, including changes in main.rs and Cargo.toml. [1] [2] [3] [4]

Geekorm-Core Changes:

• Modified geekorm-core to use tokio::sync::Mutex when the backends-tokio feature is enabled, including changes in libsql.rs. [1] [2] [3] [4] [5] [6]