feat(build): move nightly to testpypi

[ionmincu]

Description

Move nightly build to testpypi
See results here: https://test.pypi.org/project/uipath-langchain/#history

Development Package

• Add this package as a dependency in your pyproject.toml:

[project]
dependencies = [
  # Exact version:
  "uipath-langchain==0.0.110.dev1000990138",

  # Any version from PR
  "uipath-langchain>=0.0.110.dev1000990000,<0.0.110.dev1001000000"
]

[[tool.uv.index]]
name = "testpypi"
url = "https://test.pypi.org/simple/"
publish-url = "https://test.pypi.org/legacy/"
explicit = true

[tool.uv.sources]
uipath-langchain = { index = "testpypi" }