Update to livekit-agents 1.4, add Python 3.14 support

Author: Topherhindman

pyproject.toml

@@ -6,10 +6,10 @@ build-backend = "setuptools.build_meta"
 name = "agent-starter-python"
 version = "1.0.0"
 description = "Simple voice AI assistant built with LiveKit Agents for Python"
-requires-python = ">=3.10, <3.14"
+requires-python = ">=3.10, <3.15"
 
 dependencies = [
-    "livekit-agents[silero,turn-detector]~=1.3",
+    "livekit-agents[silero,turn-detector]~=1.4",
     "livekit-plugins-noise-cancellation~=0.2",
     "python-dotenv",
 ]