Prepare azcore v1.3.1 for release (#19929)

Author: chlowell

sdk/azcore/CHANGELOG.md

@@ -1,12 +1,6 @@
 # Release History
 
-## 1.3.1 (Unreleased)
-
-### Features Added
-
-### Breaking Changes
-
-### Bugs Fixed
+## 1.3.1 (2023-02-02)
 
 ### Other Changes
 * Update dependencies to latest versions.