[ruby/rubygems] Fix grammar in gem installer cache comment

Change "and lock the mutex" to "and to lock the mutex" for correct
parallel infinitive structure.

ruby/rubygems@94f9267b72

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

lib/bundler/source/rubygems.rb

@@ -513,7 +513,7 @@ def extension_cache_slug(spec)
 
       # We are using a mutex to read and write from/to the hash.
       # The reason this double synchronization was added is for performance
-      # and lock the mutex for the shortest possible amount of time. Otherwise,
+      # and to lock the mutex for the shortest possible amount of time. Otherwise,
       # all threads are fighting over this mutex and when it gets acquired it gets locked
       # until a thread finishes downloading a gem, leaving the other threads waiting
       # doing nothing.