Bump HF Spaces sdk_version to 5.38.2

Aligns the runtime image with requirements.txt (gradio>=5.33.1) so
pip no longer has to upgrade gradio on top of the older 5.23.1 image
during Space startup.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -4,7 +4,7 @@ emoji: 📊
 colorFrom: green
 colorTo: green
 sdk: gradio
-sdk_version: 5.23.1
+sdk_version: 5.38.2
 app_file: app.py
 pinned: true
 license: apache-2.0