Allow release-build-wordpress.sh to specify whether to build a beta

Author: mokagio

.buildkite/commands/release-build-wordpress.sh

@@ -21,4 +21,5 @@ bundle exec fastlane run configure_apply
 echo "--- :hammer_and_wrench: Building"
 bundle exec fastlane build_and_upload_app_store_connect \
   skip_confirm:true \
-  create_gh_release:true
+  create_gh_release:true \
+  beta_release:${1:-true} # use first call param, default to true for safety