Pin openai<2.0: version 2.x requires jiter which fails to build on PyPy

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: vthorsteinsson

requirements.txt

@@ -27,7 +27,7 @@ rjsmin>=1.2.4
 python-youtube==0.9.1
 country-list>=1.1.0
 # For OpenAI GPT support
-openai>=1.60.0
+openai>=1.40.0,<2.0
 httpx>=0.27.2
 # Ours
 reynir>=3.5.7