build: update releaserc to ensure we have a "release" branch (#3345)

Semantic release requires at least 1 branch be configured as "release" (see https://github.com/semantic-release/semantic-release/blob/master/docs/usage/workflow-configuration.md#branches-properties)

Before this change we had 2 "maintenance" branches and 1 "pre-release" branch, but no "release" branch. This led to an error https://github.com/openedx/paragon/actions/runs/12286316911/job/34286199225

.releaserc

@@ -1,7 +1,7 @@
 {
   "branches": [
     { "name": "release-22.x", "range": "22.x", "channel": "22.x" },
-    { "name": "release-23.x", "range": "23.x" },
+    { "name": "release-23.x" },
     { "name": "next", "prerelease": true, "channel": "next" }
   ],
   "plugins": [