[rubygems/rubygems] Remove comment that seems no longer accurate

We require things inline or autoload them for efficiency and to avoid as
much as possible conflicting with user's choice of gems.

But I removed the require and observed no deadlocks when activating
gems.

https://github.com/rubygems/rubygems/commit/7d6333e842

lib/rubygems/source/git.rb

@@ -225,7 +225,7 @@ class Gem::Source::Git < Gem::Source
   # A hash for the git gem based on the git repository URI.
 
   def uri_hash # :nodoc:
-    require 'digest' # required here to avoid deadlocking in Gem.activate_bin_path (because digest is a gem on 2.5+)
+    require 'digest'
 
     normalized =
       if @repository =~ %r{^\w+://(\w+@)?}