chore: update current maintainer (#1213)

Author: arithmetic1728

packages/google-auth/README.rst

@@ -52,14 +52,15 @@ Google Auth Python Library has usage and reference documentation at https://goog
 
 Current Maintainers
 -------------------
-- `@busunkim96 <https://github.com/busunkim96>`_ (Bu Sun Kim)
+- googleapis-auth@google.com
 
 Authors
 -------
 
 - `@theacodes <https://github.com/theacodes>`_ (Thea Flowers)
 - `@dhermes <https://github.com/dhermes>`_ (Danny Hermes)
 - `@lukesneeringer <https://github.com/lukesneeringer>`_ (Luke Sneeringer)
+- `@busunkim96 <https://github.com/busunkim96>`_ (Bu Sun Kim)
 
 Contributing
 ------------