fix: Update package to be from git repo

Author: anubhav756

packages/toolbox-langchain/pyproject.toml

@@ -9,7 +9,8 @@ authors = [
     {name = "Google LLC", email = "[email protected]"}
 ]
 dependencies = [
-    "toolbox-core>=0.1.0,<1.0.0",
+    # "toolbox-core>=0.1.0,<1.0.0",
+    "toolbox-core=git+https://github.com/googleapis/mcp-toolbox-sdk-python.git#egg=toolbox-core&subdirectory=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",