v3.9.3
script/backport-pr: cherry-pick the commit properly
Updated the scripts shebang for portability
add test to build the default site
Define path with __dir__ (#6087)
Upgrade to Cucumber 3.0 (#6395)
Rewrite kramdown and rouge versions in script/default-site
Update fmt (#6514)
Backport #7948 for v3.8.x (#8125)
Default options for script/proof (#5995)
Check for Ruby first, then JRuby
Rewrite `script/rubyprof` as a Ruby script (#6813)
script/test: add missing whitespace
Try to cleanup the Gemfile... again.
Fix response header for content served via `jekyll serve` (#8965)