require python >=3.9

setup.py

@@ -91,7 +91,7 @@ def create_extensions():
             "pooch"
         ]
     },
-    python_requires=">=3.7",
+    python_requires=">=3.9",  # transonic requires >= 3.9
     cmdclass={"build_ext": ParallelBuildExt},
     ext_modules=create_extensions(),
 )