Update README system requirements to match current requirements.txt

[v1shay]

The README's System Requirements table appears to describe an older environment:

• Model Conversion lists Python 3.8 and coremltools 7.0.
• The current requirements.txt requires coremltools>=8.0 and pins diffusers[torch]==0.30.2.

Could the table be updated to reflect the currently supported dependency set, or clearly labeled as historical requirements for the benchmark/conversion workflow? Keeping the README and install requirements aligned would help new users avoid resolving an environment that cannot satisfy the repository's current dependencies.