Upgrade rbenv - check version of rbenv and upgrade if necessary using brew
Upgrade ruby - check current version of ruby being used by rbenv and upgrade if necessary
# show current installed versions
rbenv versions
# list available versions
rbenv install -l
# install latest available version
rbenv install 3.2.2
# set version to be used
rbenv global 3.2.2
Open terminal in ruby project, install gems with bundle install
If message show that this involved downgrading bundler, then consider bundle upgrade --bundler to upgrade
Update the pinned gems in the Gemfile to the lastest version and go for a bundle update jekyll