community[patch]: Fix Playwright Tools bug with Pydantic schemas (#27050)

- Add tests for Playwright tools schema serialization
- Introduce base empty args Input class for BaseBrowserTool

Test Plan: `poetry run pytest
tests/unit_tests/tools/playwright/test_all.py`

Fixes #26758

---------

Co-authored-by: Erick Friis <erick@langchain.dev>
Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>

libs/community/tests/unit_tests/tools/playwright/test_all.py

@@ -0,0 +1,26 @@
+"""Test Playwright's Tools."""
+
+from unittest.mock import Mock
+
+import pytest
+
+from langchain_community.agent_toolkits import PlayWrightBrowserToolkit
+
+
+@pytest.mark.requires("playwright")
+@pytest.mark.requires("bs4")
+def test_playwright_tools_schemas() -> None:
+    """Test calling 'tool_call_schema' for every tool to check to init issues."""
+
+    from playwright.sync_api import Browser
+
+    sync_browser = Mock(spec=Browser)
+    tools = PlayWrightBrowserToolkit.from_browser(sync_browser=sync_browser).get_tools()
+
+    for tool in tools:
+        try:
+            tool.tool_call_schema
+        except Exception as e:
+            raise AssertionError(
+                f"Error for '{tool.name}' tool: {type(e).__name__}: {e}"
+            ) from e