Two follow-ups to the 7.0.240 release CI failures:

1. release-on-maven-central.yml: pin maven-resources-plugin to 3.3.1
   in the cloned cn1-maven-archetypes pom before mvn deploy. Maven
   Central currently advertises maven-resources-plugin 4.0.0-beta-1
   as the latest release; that build requires Java 17 + Maven 4 and
   fails the archetype deploy on the Java 8 / Maven 3.9 runner.
   Injecting a top-level pluginManagement entry forces 3.3.1.

2. initializr-cn1-version-pr.yml: also wait for codenameone-maven-plugin
   to appear on Maven Central before opening the PR. The dev-guide.pdf
   wait alone wasn't enough -- PR-triggered workflows like
   cn1playground-language try to resolve the new plugin version from
   Central as soon as the PR opens, and Sonatype Central to repo1
   propagation can take 30+ minutes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>