make status reaction count limit configurable

.env.production.sample

@@ -269,6 +269,9 @@ MAX_POLL_OPTIONS=5
 # Maximum allowed poll option characters
 MAX_POLL_OPTION_CHARS=100
 
+# Maximum number of emoji reactions per toot and user (minimum 1)
+MAX_STATUS_REACTIONS=8
+
 # Maximum image and video/audio upload sizes
 # Units are in bytes
 # 1048576 bytes equals 1 megabyte

app/validators/status_reaction_validator.rb

@@ -3,7 +3,7 @@
 class StatusReactionValidator < ActiveModel::Validator
   SUPPORTED_EMOJIS = Oj.load_file(Rails.root.join('app', 'javascript', 'mastodon', 'features', 'emoji', 'emoji_map.json').to_s).keys.freeze
 
-  LIMIT = 8
+  LIMIT = [1, (ENV['MAX_STATUS_REACTIONS'] || 1).to_i].max
 
   def validate(reaction)
     return if reaction.name.blank?