Be more explicit about supporting Python 3.13 or not

[leofontenelle]

pyproject.toml says requires-python = ">=3.8" as well as

classifiers = [
    # snip
    "Programming Language :: Python :: 3",
    "Programming Language :: Python :: 3.10",
    "Programming Language :: Python :: 3.11",
    "Programming Language :: Python :: 3.12",
    "Programming Language :: Python :: 3.8",
    "Programming Language :: Python :: 3.9",
    # snip
]

and documentation says "Python 3.7 to 3.11 and pip."

I guess you will want to update the documentation to mention at least Python 3.12 and, if Python 3.13 and, who knows, 3.14 are supported, mention them as well. Same for classifiers in pyproject.toml