Docs/add rust version requirement

[Aditya30ag]

Description

This PR updates the documentation to clarify the minimum supported Rust version (1.89.0) and adds instructions to update Rust using rustup update stable when an older version is installed.

Checklist

• I have run ./scripts/precommit.sh and addressed all comments

[domenukk]

I fear that we'll forget about updating the rust version in docs when we push the min version :D

[Aditya30ag]

your point is absolutely valid we can do one thing instead explicitly point one version we can ask to update the rust version if it become old