Add the release note for 1.31.2 (line#6013)

Author: minwoox

Diff for: site/src/pages/release-notes/1.31.2.mdx

@@ -0,0 +1,18 @@
+---
+date: 2024-12-03
+---
+
+## 🛠️ Bug fixes
+
+- Fixed a bug where stale endpoints remained when a Kubernetes service was updated. #6012
+- Fix a bug where weights could unintentionally be set to 0 in ramping-up strategies. #6014
+
+## 🙇 Thank you
+
+<ThankYou usernames={[
+  'ikhoon',
+  'jrhee17',
+  'mauhiz',
+  'minwoox',
+  'trustin'
+]} />