Reword jobserver comment to satisfy quality spec

Bundler's quality spec rejects weak modifiers in lib source, and the
connect_to_jobserver comment used "the pool we just created". Name
ParallelInstaller instead so the meaning stays clear without "just".

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: hsbt

bundler/lib/bundler/rubygems_gem_installer.rb

@@ -189,7 +189,7 @@ def connect_to_jobserver
       return unless ENV["MAKEFLAGS"]
       # We append our own --jobserver-auth, so read the last one. Otherwise a
       # parent jobserver's descriptors (e.g. `bundle install` run under
-      # `make -j`) would be picked up instead of the pool we just created.
+      # `make -j`) would be picked up instead of the pool ParallelInstaller created.
       read_fd, write_fd = ENV["MAKEFLAGS"].scan(/--jobserver-auth=(\d+),(\d+)/).last
 
       return unless read_fd && write_fd