setup-poetry: Change default Poetry version to 2.1.4

[bkeryan]

What does this Pull Request accomplish?

Upgrade default Poetry version to 2.1.4.

Why should this Pull Request be merged?

Align with NI's internal Poetry versioning policy, but also pull in the 2.1.4 patch, which fixes a major regression in poetry env use.

Potentially fix regressions related to unlocked dependencies (or maybe find new ones).

What testing has been done?

PR build.

[bkeryan]

pyenv local xxx and poetry env use python doesn't work with 2.1.3. It uses the Poetry venv's Python, not the local Python. I think we should use 2.1.4, even if NI's internal tooling is still using 2.1.3.

poetry 2.1.3:

PS C:\dev\nitypes-python> pyenv local pypy3.11-v7.3.19-win64
PS C:\dev\nitypes-python> poetry env use python
Creating virtualenv nitypes in C:\dev\nitypes-python\.venv
Using virtualenv: C:\dev\nitypes-python\.venv
PS C:\dev\nitypes-python> poetry run python
Python 3.11.9 (tags/v3.11.9:de54cf5, Apr  2 2024, 10:12:12) [MSC v.1938 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> quit()

poetry 2.1.4:

PS C:\dev\nitypes-python> pyenv local pypy3.11-v7.3.19-win64
PS C:\dev\nitypes-python> poetry env use python
Creating virtualenv nitypes in C:\dev\nitypes-python\.venv
Using virtualenv: C:\dev\nitypes-python\.venv
PS C:\dev\nitypes-python> poetry run python
Python 3.11.11 (0253c85bf5f8, Feb 26 2025, 10:43:25)
[PyPy 7.3.19 with MSC v.1941 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>>

[mshafer-NI]

Please fix the title. (will open an issue for tracking)