Read the Anthropic key from either header in the AG2 test

Anthropic's SDK 2.3.0, which CI now installs for the AG2 harness, sends the
key as Authorization: Bearer instead of x-api-key. The agent's key still
reaches Anthropic; the test only looked for the old header, so it failed on
every pull request. It now accepts either, and passes with Anthropic's SDK
1.17.0 and 2.3.0 alike.

(cherry picked from commit a1391e7)

Author: davidmckayv

agent-ag2/tests/test_main.py

@@ -190,7 +190,11 @@ def test_an_anthropic_key_uses_the_official_endpoint_when_compose_sets_a_blank_u
 
     async def respond(transport, request):
         body = json.loads(request.content)
-        seen.append((str(request.url), request.headers.get("x-api-key"), body["model"]))
+        # Anthropic's SDK sends the key as `x-api-key` up to 1.x and as `Authorization: Bearer` from
+        # 2.x; either is the key reaching Anthropic, which is what this test is about.
+        bearer = request.headers.get("authorization") or ""
+        key = request.headers.get("x-api-key") or bearer.removeprefix("Bearer ") or None
+        seen.append((str(request.url), key, body["model"]))
         return httpx2.Response(
             200,
             request=request,