Publish to GitHub packages only when RC branch is pushed

Use plain RC branch name as version during build

See #356

.github/workflows/publish.yml

@@ -1,6 +1,8 @@
 name: Publish package to GitHub Packages
 on:
-  push
+  push:
+    branches:
+      - '*-rc*'
 jobs:
   publish:
     runs-on: ubuntu-latest

build.gradle

@@ -307,6 +307,10 @@ def getSnapshotVersion() {
     logger.lifecycle('Release branch found')
     return "${extractVersionFromBranch(grgit.branch.current().name)}-SNAPSHOT"
   }
+  if (grgit.branch.current().name.contains('-rc')) {
+    logger.lifecycle('Release candidate branch found')
+    return "${grgit.branch.current().name}"
+  }
   logger.lifecycle('Feature branch found')
   return "feature-${grgit.branch.current().name}-SNAPSHOT"
 }