fix(converse/transformation.py): support bedrock apac cross region inference

Fixes https://github.com/BerriAI/litellm/issues/6905

litellm/llms/bedrock/chat/converse_transformation.py

@@ -458,7 +458,7 @@ class AmazonConverseConfig:
         """
         Abbreviations of regions AWS Bedrock supports for cross region inference
         """
-        return ["us", "eu"]
+        return ["us", "eu", "apac"]
 
     def _get_base_model(self, model: str) -> str:
         """

tests/llm_translation/test_bedrock_completion.py

@@ -1243,6 +1243,19 @@ def test_bedrock_cross_region_inference(model):
     )
 
 
+@pytest.mark.parametrize(
+    "model, expected_base_model",
+    [
+        (
+            "apac.anthropic.claude-3-5-sonnet-20240620-v1:0",
+            "anthropic.claude-3-5-sonnet-20240620-v1:0",
+        ),
+    ],
+)
+def test_bedrock_get_base_model(model, expected_base_model):
+    assert litellm.AmazonConverseConfig()._get_base_model(model) == expected_base_model
+
+
 from litellm.llms.prompt_templates.factory import _bedrock_converse_messages_pt