Use CI_CD_DEFAULT_ANTHROPIC_MODEL env var in live anthropic CI tests

Replace hardcoded anthropic model names in the live-call CircleCI tests
with the CI_CD_DEFAULT_ANTHROPIC_MODEL env var (falling back to the
current default) so a model deprecation no longer requires a code change;
the model can be updated from the CircleCI project settings instead.

Only live-call sites are migrated. Tests that assert on a specific model
(metadata lookups, dict conversion, route parsing) or that require a
capability tied to a specific model (tool search needs Sonnet/Opus 4.5)
are left pinned.

tests/local_testing/test_router_budget_limiter.py

@@ -153,7 +153,7 @@ async def test_provider_budgets_e2e_test_expect_to_fail():
 
     response = await router.acompletion(
         messages=[{"role": "user", "content": "Hello, how are you?"}],
-        model="anthropic/claude-sonnet-4-5-20250929",
+        model=f"anthropic/{os.environ.get('CI_CD_DEFAULT_ANTHROPIC_MODEL', 'claude-haiku-4-5-20251001')}",
     )
     print(response)
 
@@ -163,7 +163,7 @@ async def test_provider_budgets_e2e_test_expect_to_fail():
         with pytest.raises(Exception) as exc_info:
             response = await router.acompletion(
                 messages=[{"role": "user", "content": "Hello, how are you?"}],
-                model="anthropic/claude-sonnet-4-5-20250929",
+                model=f"anthropic/{os.environ.get('CI_CD_DEFAULT_ANTHROPIC_MODEL', 'claude-haiku-4-5-20251001')}",
             )
             print(response)
             print("response.hidden_params", response._hidden_params)

tests/openai_endpoints_tests/test_e2e_openai_responses_api.py

@@ -1,3 +1,5 @@
+import os
+
 import httpx
 from openai import OpenAI, BadRequestError
 import pytest
@@ -124,7 +126,7 @@ def test_bad_request_bad_param_error():
 def test_anthropic_with_responses_api():
     client = get_test_client()
     response = client.responses.create(
-        model="anthropic/claude-sonnet-4-5-20250929",
+        model=f"anthropic/{os.environ.get('CI_CD_DEFAULT_ANTHROPIC_MODEL', 'claude-haiku-4-5-20251001')}",
         input="just respond with the word 'ping'",
         previous_response_id="hi",
     )

tests/pass_through_tests/test_anthropic_passthrough_basic.py

@@ -1,3 +1,5 @@
+import os
+
 from base_anthropic_messages_test import BaseAnthropicMessagesTest
 import anthropic
 
@@ -21,7 +23,7 @@ class TestAnthropicMessagesEndpoint(BaseAnthropicMessagesTest):
     def test_anthropic_messages_to_wildcard_model(self):
         client = self.get_client()
         response = client.messages.create(
-            model="anthropic/claude-haiku-4-5-20251001",
+            model=f"anthropic/{os.environ.get('CI_CD_DEFAULT_ANTHROPIC_MODEL', 'claude-haiku-4-5-20251001')}",
             messages=[{"role": "user", "content": "Hello, world!"}],
             max_tokens=100,
         )