Add GPT-5.4 to verified models (#2487)

Co-authored-by: openhands <openhands@all-hands.dev>

Author: juanmichelini

openhands-sdk/openhands/sdk/llm/utils/verified_models.py

@@ -1,4 +1,5 @@
 VERIFIED_OPENAI_MODELS = [
+    "gpt-5.4",
     "gpt-5.2",
     "gpt-5.2-codex",
     "gpt-5.1",
@@ -65,6 +66,7 @@
 VERIFIED_OPENHANDS_MODELS = [
     "claude-opus-4-6",
     "claude-sonnet-4-5-20250929",
+    "gpt-5.4",
     "gpt-5.2",
     "gpt-5.2-codex",
     "minimax-m2.5",