Upgrade Jekyll to 4.3.3 to fix Ruby logger issue

I (and others online) have gotten this error on a variety of repos running `bundle exec jekyll build` on Jekyll 4.3.2 with Ruby 3.3.0:
> C:/Ruby33-x64/lib/ruby/3.3.0/logger.rb:384:in `level': undefined method `[]' for nil

The fix is simple: In Gemfile.lock, change line 24 to:
> jekyll (4.3.3)

This has been solved for a couple years now, and seems to have fixed it on my computer.