add python version support range to pyproject.toml (#903)

Author: trim21

bindings/python/pyproject.toml

@@ -23,6 +23,7 @@ build-backend = "maturin"
 name = "pyiceberg_core"
 version = "0.4.0"
 readme = "project-description.md"
+requires-python = "~=3.9"
 classifiers = [
   "Development Status :: 4 - Beta",
   "Intended Audience :: Developers",