Update ollama.py with optional raw setting. (#21486)

Ollama has a raw option now. 

https://github.com/ollama/ollama/blob/main/docs/api.md

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---------

Co-authored-by: Isaac Francisco <78627776+isahers1@users.noreply.github.com>
Co-authored-by: isaac hershenson <ihershenson@hmc.edu>

libs/community/tests/unit_tests/llms/test_ollama.py

@@ -101,6 +101,7 @@ def test_handle_kwargs_top_level_parameters(monkeypatch: MonkeyPatch) -> None:
             "system": "Test system prompt",
             "template": None,
             "keep_alive": None,
+            "raw": None,
         }
         assert stream is True
         assert timeout == 300
@@ -149,6 +150,7 @@ def test_handle_kwargs_with_unknown_param(monkeypatch: MonkeyPatch) -> None:
             "system": None,
             "template": None,
             "keep_alive": None,
+            "raw": None,
         }
         assert stream is True
         assert timeout == 300
@@ -181,6 +183,7 @@ def test_handle_kwargs_with_options(monkeypatch: MonkeyPatch) -> None:
             "system": None,
             "template": None,
             "keep_alive": None,
+            "raw": None,
         }
         assert stream is True
         assert timeout == 300