docs(google-cloud-dns): sync README.rst to docs folder

Author: chalmerlowe

packages/google-cloud-dns/docs/README.rst

@@ -60,14 +60,14 @@ Supported Python Versions
 Our client libraries are compatible with all current `active`_ and `maintenance`_ versions of
 Python.
 
-Python >= 3.9
+Python >= 3.10
 
 .. _active: https://devguide.python.org/devcycle/#in-development-main-branch
 .. _maintenance: https://devguide.python.org/devcycle/#maintenance-branches
 
 Unsupported Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Python <= 3.8
+Python <= 3.9
 
 If you are using an `end-of-life`_
 version of Python, we recommend that you update as soon as possible to an actively supported version.