fix: fixed the dockerfile to preload the ruby library into the REPL environment

Author: mridang

Dockerfile

@@ -5,4 +5,4 @@ RUN rm -f *.gem
 RUN gem build *.gemspec
 RUN gem install *.gem
 RUN ruby -e "require 'zitadel_client'"
-CMD ["irb"]
+CMD ["irb", "-r", "zitadel_client"]