[PyCon DE Sprints] Bump minimum Python version to 3.11

[NMertsch]

Implicitly, this is already the case due to the dependency on 'conda-recipe-manager>=0.9'. Also:

• Remove dependency tomli (Python 3.11 includes tomllib)
• Remove dependency backports.strenum (Python 3.11 includes enum.StrEnum)
• Disable ruff rules UP007 and UP045 (deferred to another PR to keep this one short and focused)
  • UP007: typing.Union[A, B] -> A | B
  • UP045: typing.Optional[A] -> A | None

Checklist

• Added a news entry
• Regenerated schema JSON if schema altered (python -m conda_smithy.schema)

[beckermr]

@conda-forge/core are we ok bumping smithy past our minimum supported python version in our pinnings? That one is python 3.10.

[beckermr]

Note that conda-recipe-manager is an optional dep.

[jaimergp]

Note that conda-recipe-manager is an optional dep.

Yea, I don't mind skipping a few months of support (3.10 goes EOL in October). We have been testing all PRs with Python 3.11 for a while (since October 2024), so if it works with Python 3.10... we don't really know beyond what we are testing in the feedstock.

At the same time we may be able to offer better granularity for optional dependencies with the Pixi PR at #2525.