models: stop saving IP addresses in version tables.

Mark various `creator_ip_addr` and `updater_ip_addr` columns as ignored
and stop updating them in preparation for dropping them.

test/factories/comment.rb

@@ -2,7 +2,6 @@ FactoryBot.define do
   factory(:comment) do |f|
     creator
     post
-    creator_ip_addr { FFaker::Internet.ip_v4_address }
     body {FFaker::Lorem.sentences.join(" ")}
   end
 end

test/factories/dmail.rb

@@ -3,7 +3,6 @@ FactoryBot.define do
     owner factory: :user
     from factory: :user
     to factory: :user
-    creator_ip_addr { FFaker::Internet.ip_v4_address }
     title {FFaker::Lorem.words.join(" ")}
     body {FFaker::Lorem.sentences.join(" ")}
   end

test/factories/post.rb

@@ -2,7 +2,6 @@ FactoryBot.define do
   factory(:post) do
     md5 { SecureRandom.hex(32) }
     uploader
-    uploader_ip_addr {"127.0.0.1"}
     tag_string {"tag1 tag2"}
     tag_count {2}
     tag_count_general {2}

test/factories/upload.rb

@@ -1,7 +1,6 @@
 FactoryBot.define do
   factory(:upload) do
     uploader factory: :user
-    uploader_ip_addr { "127.0.0.1" }
 
     status { "pending" }
     source { "https://cdn.donmai.us/original/d3/4e/d34e4cf0a437a5d65f8e82b7bcd02606.jpg" }