[BUG] - Update ratatui dependency to 0.26

[airstrike]

Description

Version 1.9.1 of tui-realm is pinning the ratatui dependency to 0.23 which was released in Aug 28, 2023. This makes it harder to port code from projects that use ratatui to use tui-realm

Steps to reproduce

I came across this when I tried to call Paragraph::new("𝑓𝑥".to_string()).centered(), which is possible in ratatui 0.26 but not in 0.23 since .centered() had not yet been implemented.

See https://github.com/ratatui-org/ratatui/blob/c12bcfefa26529610886040bd96f2b6762436b15/src/widgets/paragraph.rs#L224-L237

Expected behaviour

I expected Paragraph::new("𝑓𝑥".to_string()).centered() to work as advertised.

Environment

• OS: Mac OS
• Architecture: Apple Silicon
• Rust version: rustc 1.76.0 (07dca489a 2024-02-04)
• tui-realm version: 1.9.1