feat: add support for python 3.13

[alexshanabrook]

Hi! Our project has already upgraded to python 3.13 but this library doesn't support it. Could support be added for python 3.13 any time soon? Thank you!

[chalmerlowe]

It is on our roadmap to upgrade all the python-bigquery-* and related libraries (e.g. python-db-dtypes-pandas) to Python 3.13 as soon as we can. I have some pressing issues I am working, so I don't feel comfortable providing an exact date at this time.

[MaxG87]

I just wanted to say that I am too are hold back by this. I have a project I would like to update to Python 3.13 but cannot because it uses python-bigquery-sqlalchemy. Additionally just today Debian Trixie (testing) started to drop Python 3.12 and to provide 3.13 only. Thus, I now have to find some way around these limitations.

I wanted to mention this article about upper version bounds. It argues that using upper limits is not very fitting for Python's ecosystem and I start to see the point.

Applying the article's arguments here: It may be unlikely that Python 3.13 really would break something. If so, users could fix that on their ends. With the upper limit in place, there is nothing we can do apart from forking or waiting.

[sonnysideup]

Or, at the very least, indicate the top range value for your supported Python version.

https://github.com/googleapis/python-bigquery-sqlalchemy?tab=readme-ov-file#supported-python-versions