Remove pinned python version from black precommit hook

[olivialynn]

@camposandro and I have run into this with a couple incubees.

In the precommit template (https://github.com/lincc-frameworks/python-project-template/blob/main/python-project-template/.pre-commit-config.yaml.jinja), we set up the black hook with the following (note the last line, with language_version):

{%- if 'black' in enforce_style %}
    # Analyze the code style and report code that doesn't adhere.
  - repo: https://github.com/psf/black
    rev: 23.7.0
    hooks:
      - id: black-jupyter
        name: Format code using black
        types_or: [python, pyi, jupyter]
        # It is recommended to specify the latest version of Python
        # supported by your project here, or alternatively use
        # pre-commit's default_language_version, see
        # https://pre-commit.com/#top_level-default_language_version
        language_version: python{{ py.pref(python_versions) }}
{%- endif %}

And two users have ended up with some version of language_version: 3.11, which caused errors for them.

We should either remove this line, or make it not do this kind of behavior