Update MIGRATION.md

Author: habara-k

MIGRATION.md

@@ -734,18 +734,3 @@ response = line_bot_api.reply_message_with_http_info(
 print(response.status_code)                     # HTTP status code
 print(response.headers.get('x-line-request-id')) # Request ID
 ```
-
----
-
-## Suppressing deprecation warnings
-
-During migration, you may see deprecation warnings when using the old `linebot` modules. To suppress them:
-
-```python
-import warnings
-from linebot import LineBotSdkDeprecatedIn30
-
-warnings.filterwarnings("ignore", category=LineBotSdkDeprecatedIn30)
-```
-
-> **Tip:** Only suppress these warnings temporarily. Once your migration is complete, remove both the warning filter and the deprecated imports.