core: Improve mypy config (#30737)

* Cleanup mypy config
* Add mypy `strict` rules except `disallow_any_generics`,
`warn_return_any` and `strict_equality` (TODO)
* Add mypy `strict_byte` rule
* Add mypy support for PEP702 `@deprecated` decorator
* Bump mypy version to 1.15

---------

Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>

libs/core/tests/benchmarks/test_async_callbacks.py

@@ -49,7 +49,7 @@ async def test_async_callbacks_in_sync(benchmark: BenchmarkFixture) -> None:
     infinite_cycle = cycle([AIMessage(content=" ".join(["hello", "goodbye"] * 500))])
     model = GenericFakeChatModel(messages=infinite_cycle)
 
-    @benchmark
+    @benchmark  # type: ignore[misc]
     def sync_callbacks() -> None:
         for _ in range(5):
             for _ in model.stream("meow", {"callbacks": [MyCustomAsyncHandler()]}):

libs/core/tests/benchmarks/test_imports.py

@@ -49,6 +49,6 @@ from pytest_benchmark.fixture import BenchmarkFixture  # type: ignore[import-unt
 )
 @pytest.mark.benchmark
 def test_import_time(benchmark: BenchmarkFixture, import_path: str) -> None:
-    @benchmark
+    @benchmark  # type: ignore[misc]
     def import_in_subprocess() -> None:
         subprocess.run([sys.executable, "-c", import_path], check=False)