script/fixes/123_refresh_media_metadata.rb: don't wrap in transaction.

Don't wrap the metadata refresh script in a transaction because it could
be a very long running operation and it's not good to leave a transaction
open that long.

script/fixes/123_refresh_media_metadata.rb

@@ -2,11 +2,10 @@
 
 require_relative "base"
 
-with_confirmation do
+condition = ENV.fetch("COND", "TRUE")
-  condition = ENV.fetch("COND", "TRUE")
+fix = ENV.fetch("FIX", "false").truthy?
-  fix = ENV.fetch("FIX", "false").truthy?
 
-  MediaAsset.active.where(condition).find_each do |asset|
+MediaAsset.active.where(condition).find_each do |asset|
   variant = asset.variant(:original)
   media_file = variant.open_file
 
@@ -30,5 +29,4 @@ with_confirmation do
   end
 
   media_file.close
-  end
 end