Update readme with red python 3.13 badge, update pyproject as 3.13 un…

…supported.

README.md

@@ -1,6 +1,8 @@
 # adtl – another data transformation language
 
-[![](https://img.shields.io/badge/python-3.8+-blue.svg)](https://www.python.org/downloads/)
+[![Python 3.8+](https://img.shields.io/badge/python-3.8+-blue.svg)](https://www.python.org/downloads/)
+[![Python 3.13](https://img.shields.io/badge/python-3.13-red.svg)](https://www.python.org/downloads/release/python-3130/)
+
 [![tests](https://github.com/globaldothealth/adtl/actions/workflows/tests.yml/badge.svg)](https://github.com/globaldothealth/adtl/actions/workflows/tests.yml)
 [![codecov](https://codecov.io/gh/globaldothealth/adtl/branch/main/graph/badge.svg?token=QTD7HRR3TO)](https://codecov.io/gh/globaldothealth/adtl)
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)

pyproject.toml

@@ -14,7 +14,7 @@ authors = [
   {name = "Pip Liggins", email = "philippa.liggins@dtc.ox.ac.uk"}
 ]
 license = {file = "LICENSE"}
-requires-python = ">=3.8"
+requires-python = ">=3.8, <3.13" # 3.13 not supported by pint, so temporary upper bound
 readme = "README.md"
 classifiers = ["License :: OSI Approved :: MIT License"]
 dependencies = [