chore: merge release v2.4.0 to main

Merge google#6337

Syncs version bump and CHANGELOG from release v2.4.0 to main.

Co-authored-by: Yifan Wang <wanyif@google.com>
COPYBARA_INTEGRATE_REVIEW=google#6337 from google:release/v2.4.0 0f9ec19
PiperOrigin-RevId: 944170996

Author: 2 people

.github/.release-please-manifest.json

@@ -1,3 +1,3 @@
 {
-  ".": "2.3.0"
+  ".": "2.4.0"
 }

.github/release-please-config.json

@@ -57,5 +57,5 @@
       ]
     }
   },
-  "last-release-sha": "0cb4c814928f579bfbac9b9e1f95669e4304e089"
+  "last-release-sha": "44d747ed5eaf543b5b8d22e0088f8a7c7eeee846"
 }