Fix Pydantic class-based config deprecation warnings (#9279)

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

openhands/server/routes/manage_conversations.py

@@ -7,7 +7,7 @@ from datetime import datetime, timezone
 from fastapi import APIRouter, Depends, status
 from fastapi.responses import JSONResponse
 from jinja2 import Environment, FileSystemLoader
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 
 from openhands.core.config.llm_config import LLMConfig
 from openhands.core.logger import openhands_logger as logger
@@ -88,7 +88,7 @@ class InitSessionRequest(BaseModel):
     if os.getenv('ALLOW_SET_CONVERSATION_ID', '0') == '1':
         conversation_id: str = Field(default_factory=lambda: uuid.uuid4().hex)
 
-    model_config = {'extra': 'forbid'}
+    model_config = ConfigDict(extra='forbid')
 
 
 class ConversationResponse(BaseModel):

openhands/server/session/conversation_init_data.py

@@ -1,4 +1,4 @@
-from pydantic import Field
+from pydantic import ConfigDict, Field
 
 from openhands.integrations.provider import CUSTOM_SECRETS_TYPE, PROVIDER_TOKEN_TYPE
 from openhands.integrations.service_types import ProviderType
@@ -18,6 +18,6 @@ class ConversationInitData(Settings):
     conversation_instructions: str | None = Field(default=None)
     git_provider: ProviderType | None = Field(default=None)
 
-    model_config = {
-        'arbitrary_types_allowed': True,
-    }
+    model_config = ConfigDict(
+        arbitrary_types_allowed=True,
+    )

openhands/server/settings.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 from pydantic import (
     BaseModel,
+    ConfigDict,
     SecretStr,
 )
 
@@ -39,7 +40,7 @@ class GETSettingsModel(Settings):
     llm_api_key_set: bool
     search_api_key_set: bool = False
 
-    model_config = {'use_enum_values': True}
+    model_config = ConfigDict(use_enum_values=True)
 
 
 class CustomSecretWithoutValueModel(BaseModel):