fix: Fix local package path

Author: anubhav756

packages/toolbox-langchain/pyproject.toml

@@ -9,8 +9,7 @@ authors = [
     {name = "Google LLC", email = "[email protected]"}
 ]
 dependencies = [
-    # "toolbox-core>=0.1.0,<1.0.0",
-    "toolbox-core @ file:../toolbox-core",
+    "toolbox-core @ file:./packages/toolbox-core",
     "langchain-core>=0.2.23,<1.0.0",
     "PyYAML>=6.0.1,<7.0.0",
     "pydantic>=2.7.0,<3.0.0",