Canonical releases Real-time Ubuntu 24.04 LTS

Real-time Ubuntu 24.04 LTS integrates the PREEMPT_RT patch on AMD64 and ARM64. As the de-facto Linux real-time implementation, PREEMPT_RT increases predictability by modifying the existing kernel code. With time-bound responses for mission-critical latency requirements, Real-time Ubuntu 24.04 LTS provides deterministic processing to the most demanding workloads across industries, from manufacturing and automotive to the critical infrastructure of telco operators.

Edoardo Barbieri at the Ubuntu blog

If you need it, you need it, but it's exclusive to Ubuntu Pro. Luckily Pro is free for personal use, so if you really need Ubuntu but with a real-time kernel - based on Linux 6.8 - there's nothing stopping you.