Remove Streamlit references from requirements.txt

[DeepRatAI]

MedX uses Reflex for the UI, but requirements.txt still has:

• streamlit>=1.28.0
• streamlit-chat>=0.1.1

These are V1 leftovers and should be removed or replaced with Reflex dependencies.

[MrIridescent]

Hi! I'd like to take a look at this. I'm new to the project but I've fixed similar issues before. I'll submit a PR shortly.