feat: Add configuration option for apikey security (#322)

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

tests/test_2-urls-async-all-outputs.py

@@ -6,10 +6,15 @@ import pytest
 import pytest_asyncio
 from pytest_check import check
 
+from docling_serve.settings import docling_serve_settings
+
 
 @pytest_asyncio.fixture
 async def async_client():
-    async with httpx.AsyncClient(timeout=60.0) as client:
+    headers = {}
+    if docling_serve_settings.api_key:
+        headers["X-Api-Key"] = docling_serve_settings.api_key
+    async with httpx.AsyncClient(timeout=60.0, headers=headers) as client:
         yield client