Add Miralis to newletter

Miralis is Rust firmware that just got is v0.1 release this month.
See: https://github.com/CharlyCst/miralis

Author: CharlyCst

content/this-month/2025-05/index.md

@@ -44,6 +44,7 @@ In this section, we collect recent updates to `rustc`, `cargo`, and other toolin
   - (optional) Some additional context
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+- [Miralis, a RISC-V virtual firmware monitor](https://github.com/CharlyCst/miralis)
 
 ## `rust-osdev` Projects