multiple: enforce standards on tool_choice (#30372)

- Test if models support forcing tool calls via `tool_choice`. If they
do, they should support
  - `"any"` to specify any tool
  - the tool name as a string to force calling a particular tool
- Add `tool_choice` to signature of `BaseChatModel.bind_tools` in core
- Deprecate `tool_choice_value` in standard tests in favor of a boolean
`has_tool_choice`

Will follow up with PRs in external repos (tested in AWS and Google
already).

libs/partners/mistralai/tests/integration_tests/test_standard.py

@@ -1,6 +1,6 @@
 """Standard LangChain interface tests"""
 
-from typing import Optional, Type
+from typing import Type
 
 from langchain_core.language_models import BaseChatModel
 from langchain_tests.integration_tests import (  # type: ignore[import-not-found]
@@ -22,8 +22,3 @@ class TestMistralStandard(ChatModelIntegrationTests):
     @property
     def supports_json_mode(self) -> bool:
         return True
-
-    @property
-    def tool_choice_value(self) -> Optional[str]:
-        """Value to use for tool choice when used in tests."""
-        return "any"