Two versions of ruby installed

It seems like I have two versions of ruby installed. (3.3.0 and 2.6.10.210) How to fix that? ``` peter@mac ios % sudo gem update --system Password: Updating rubygems-update Fetching rubygems-update-3.5.6.gem ERROR: Error installing rubygems-update: There are no versions of rubygems-update (= 3.5.6) compatible with your Ruby & RubyGems rubygems-update requires Ruby version >= 3.0.0. The current ruby version is 2.6.10.210. ERROR: While executing gem ... (NoMethodError) undefined method `version' for nil:NilClass peter@mac ios % brew install ruby ==> Downloading https://formulae.brew.sh/api/formula.jws.json ################################################################################################################################################################################################################################# 100.0% ==> Downloading https://formulae.brew.sh/api/cask.jws.json ################################################################################################################################################################################################################################# 100.0% Warning: ruby 3.3.0 is already installed and up-to-date. To reinstall 3.3.0, run: brew reinstall ruby peter@mac ios % brew install rubygems-update Warning: No available formula with the name "rubygems-update". ==> Searching for similarly named formulae and casks... Error: No formulae or casks found for rubygems-update. peter@mac ios % brew install rubygems Warning: No available formula with the name "rubygems". Did you mean rubyfmt? macOS provides gem as part of Ruby. To install a newer version: brew install ruby peter@mac ios % brew upgrade ruby Warning: ruby 3.3.0 already installed peter@mac ios %