Drop old jruby support (modern have tempfile similar to mri)

lib/paperclip.rb

@@ -32,7 +32,6 @@ require 'paperclip/upfile'
 require 'paperclip/iostream'
 require 'paperclip/geometry'
 require 'paperclip/processor'
-require 'paperclip/tempfile'
 require 'paperclip/thumbnail'
 require 'paperclip/recursive_thumbnail'
 require 'paperclip/storage'

lib/paperclip/tempfile.rb

@@ -1,20 +0,0 @@
-# frozen_string_literal: true
-
-require 'English'
-
-module Paperclip
-  # Due to how ImageMagick handles its image format conversion and how Tempfile
-  # handles its naming scheme, it is necessary to override how Tempfile makes
-  # its names so as to allow for file extensions. Idea taken from the comments
-  # on this blog post:
-  # http://marsorange.com/archives/of-mogrify-ruby-tempfile-dynamic-class-definitions
-  class Tempfile < ::Tempfile
-    # это похоже актуально только для java (не проверял, в mri 3.2 точно не вызывается)
-
-    # Replaces Tempfile's +make_tmpname+ with one that honors file extensions.
-    def make_tmpname(basename, n)
-      extension = File.extname(basename)
-      sprintf("%s,%d,%d%s", File.basename(basename, extension), $PROCESS_ID, n.to_i, extension)
-    end
-  end
-end