DEV: Change fast typer trust level setting to enum type (#23429)

We have one site setting, `auto_silence_fast_typers_max_trust_level`, which expects a trust level. However, the type is set to integer, which makes it very hard for a layman to enter the correct thing.

This PR changes the type of the site setting to the `TrustLevelSetting` enum.

The use of these are interchangeable in the back-end, since `SiteSetting.auto_silence_fast_typers_max_trust_level` still returns the integer value with the enum.

config/site_settings.yml

@@ -1934,7 +1934,9 @@ spam:
   auto_respond_to_flag_actions: true
   min_first_post_typing_time: 3000
   auto_silence_fast_typers_on_first_post: true
-  auto_silence_fast_typers_max_trust_level: 0
+  auto_silence_fast_typers_max_trust_level:
+    default: 0
+    enum: "TrustLevelSetting"
   auto_silence_first_post_regex: ""
   high_trust_flaggers_auto_hide_posts: true
   cooldown_hours_until_reflag:

db/migrate/20230906030920_change_auto_silence_fast_typers_setting_to_enum_type.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+class ChangeAutoSilenceFastTypersSettingToEnumType < ActiveRecord::Migration[7.0]
+  def up
+    execute <<~SQL
+      UPDATE
+        "site_settings"
+      SET
+        "data_type" = 7
+      WHERE
+        "name" = 'auto_silence_fast_typers_max_trust_level' AND
+        "data_type" = 3
+    SQL
+  end
+
+  def down
+    execute <<~SQL
+      UPDATE
+        "site_settings"
+      SET
+        "data_type" = 3
+      WHERE
+        "name" = 'auto_silence_fast_typers_max_trust_level' AND
+        "data_type" = 7
+    SQL
+  end
+end