Update auto-merge.yml to 2.3.12 branch

(cherry picked from commit e671d667cbbf3da349bba9b68b609a1a01959c4a)

.github/workflows/auto-merge.yml

diff --git a/.github/workflows/auto-merge.yml b/.github/workflows/auto-merge.yml
index 721b1d6..1ed0a16 100644
--- a/.github/workflows/auto-merge.yml
+++ b/.github/workflows/auto-merge.yml
@@ -7,7 +7,7 @@
     branches: [ main ]
 
 env:
-  RELEASE_BRANCH: "2.3.11-release"
+  RELEASE_BRANCH: "2.3.12-release"
 
 jobs:
   test: