test(dns): Update testing constraints to 3.10 and drop 3.9

Author: chalmerlowe

packages/google-cloud-dns/pytest.ini

@@ -9,8 +9,4 @@ filterwarnings =
     # Remove once https://github.com/googleapis/python-api-common-protos/pull/187/files is merged
     ignore:.*pkg_resources.declare_namespace:DeprecationWarning
     ignore:.*pkg_resources is deprecated as an API:DeprecationWarning
-    # Remove after support for Python 3.7 is dropped
-    ignore:After January 1, 2024, new releases of this library will drop support for Python 3.7:DeprecationWarning
-    # Remove after support for Python 3.8, 3.9 and/or 3.10+ is dropped
-    ignore:\s*You are using a (non-supported )?Python version \(?3\.(8|9|1[0-9]+):DeprecationWarning
-    ignore:\s*You are using a (non-supported )?Python version \(?3\.(8|9|1[0-9]+):FutureWarning
+

packages/google-cloud-dns/testing/constraints-3.10.txt

@@ -0,0 +1,8 @@
+# This constraints file is used to check that lower bounds
+# are correct in setup.py
+# List *all* library dependencies and extras in this file.
+# Pin the version to the lower bound.
+#
+# e.g., if setup.py has "foo >= 1.14.0, < 2.0.0dev",
+# Then this file should have foo==1.14.0
+google-cloud-core==1.4.4