setup.py: Fix metadata to indicate currently supported Python >= 3.9

fixes tensorflow#2036

Signed-off-by: Ievgen Popovych <[email protected]>

setup.py

@@ -152,8 +152,6 @@ def has_ext_modules(self):
         "Intended Audience :: Science/Research",
         "License :: OSI Approved :: Apache Software License",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.7",
-        "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
@@ -168,7 +166,7 @@ def has_ext_modules(self):
     ],
     keywords="tensorflow io machine learning",
     packages=setuptools.find_packages(where=".", exclude=exclude),
-    python_requires=">=3.7, <3.13",
+    python_requires=">=3.9, <3.13",
     install_requires=install_requires,
     extras_require={
         "tensorflow": [require],