Change registrations to be disabled by default for new servers (#29280)

spec/spec_helper.rb

@@ -25,6 +25,12 @@ RSpec.configure do |config|
   config.before :suite do
     Rails.application.load_seed
     Chewy.strategy(:bypass)
+
+    # NOTE: we switched registrations mode to closed by default, but the specs
+    # very heavily rely on having it enabled by default, as it relies on users
+    # being approved by default except in select cases where explicitly testing
+    # other registration modes
+    Setting.registrations_mode = 'open'
   end
 
   config.after :suite do

spec/support/streaming_server_manager.rb

@@ -102,6 +102,13 @@ RSpec.configure do |config|
     self.use_transactional_tests = false
 
     DatabaseCleaner.cleaning do
+      # NOTE: we switched registrations mode to closed by default, but the specs
+      # very heavily rely on having it enabled by default, as it relies on users
+      # being approved by default except in select cases where explicitly testing
+      # other registration modes
+      # Also needs to be set per-example here because of the database cleaner.
+      Setting.registrations_mode = 'open'
+
       example.run
     end