fix: update type annotations to modern Python 3.10+ syntax

Author: jdrhyne

tests/integration/test_watermark_image_file_integration.py

@@ -2,7 +2,6 @@
 
 import os
 from pathlib import Path
-from typing import Optional, Union
 
 import pytest
 
@@ -11,16 +10,16 @@
 try:
     from . import integration_config  # type: ignore[attr-defined]
 
-    API_KEY: Optional[str] = integration_config.API_KEY
-    BASE_URL: Optional[str] = getattr(integration_config, "BASE_URL", None)
+    API_KEY: str | None = integration_config.API_KEY
+    BASE_URL: str | None = getattr(integration_config, "BASE_URL", None)
     TIMEOUT: int = getattr(integration_config, "TIMEOUT", 60)
 except ImportError:
     API_KEY = None
     BASE_URL = None
     TIMEOUT = 60
 
 
-def assert_is_pdf(file_path_or_bytes: Union[str, bytes]) -> None:
+def assert_is_pdf(file_path_or_bytes: str | bytes) -> None:
     """Assert that a file or bytes is a valid PDF."""
     if isinstance(file_path_or_bytes, str):
         with open(file_path_or_bytes, "rb") as f: