Preparing the release of absl-py 2.0.0.

PiperOrigin-RevId: 566462829

Author: yilei

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com).
 
 ## Unreleased
 
+Nothing notable unreleased.
+
+## 2.0.0 (2023-09-19)
+
 ### Changed
 
 *   `absl-py` no longer supports Python 3.6. It has reached end-of-life for more

setup.py

@@ -45,7 +45,7 @@
 
 setuptools.setup(
     name='absl-py',
-    version='2.0.0.dev0',
+    version='2.0.0',
     description=(
         'Abseil Python Common Libraries, '
         'see https://github.com/abseil/abseil-py.'