More updates to capitalize on PyCon 2025 success

- Update python version in pyproject.toml to [python >=3.11](https://github.com/projectmesa/mesa-examples/blob/c70a40123105408d6066acfd5bfce3778cb955b7/pyproject.toml#L12)

- increase [mesa-examples version](https://github.com/projectmesa/mesa-examples/blob/c70a40123105408d6066acfd5bfce3778cb955b7/pyproject.toml#L16)

- ensure pypi release

- finish update workflow

Start with pyproject.toml, especially the Python requirement and mesa-examples version at the referenced lines. Then inspect the existing update workflow and release configuration, and verify that the updated package can be published to PyPI; done means all listed version, workflow, and release tasks are complete.

Written by the indexing model from the issue text.