Fix prepare-release-branch, update changelog for 1.23.1 release (#39)

Author: jack-berg

.github/workflows/prepare-release-branch.yml

@@ -83,7 +83,7 @@ jobs:
       - name: Set environment variables
         run: |
           version=$(.github/scripts/get-version.sh)
-          if [[ ! $version =~ ^([0-9]+)\.([0-9]+)\.0$ ]]; then
+          if [[ ! $version =~ ^([0-9]+)\.([0-9]+)\.([0-9]+)$ ]]; then
             echo "unexpected version: $version"
             exit 1
           fi

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+## Version 1.23.1 (2023-11-21)
+
 * Extended jinja template to generate template-type semantic attributes.
   ([#24](https://github.com/open-telemetry/semantic-conventions-java/pull/24))
 * Update to semconv 1.23.1