Update Mastodon to Rails 6.1 (#15910)

* Update devise-two-factor to unreleased fork for Rails 6 support

Update tests to match new `rotp` version.

* Update nsa gem to unreleased fork for Rails 6 support

* Update rails to 6.1.3 and rails-i18n to 6.0

* Update to unreleased fork of pluck_each for Ruby 6 support

* Run "rails app:update"

* Add missing ActiveStorage config file

* Use config.ssl_options instead of removed ApplicationController#force_ssl

Disabled force_ssl-related tests as they do not seem to be easily testable
anymore.

* Fix nonce directives by removing Rails 5 specific monkey-patching

* Fix fixture_file_upload deprecation warning

* Fix yield-based test failing with Rails 6

* Use Rails 6's index_with when possible

* Use ActiveRecord::Cache::Store#delete_multi from Rails 6

This will yield better performances when deleting an account

* Disable Rails 6.1's automatic preload link headers

Since Rails 6.1, ActionView adds preload links for javascript files
in the Links header per default.

In our case, that will bloat headers too much and potentially cause
issues with reverse proxies. Furhermore, we don't need those links,
as we already output them as HTML link tags.

* Switch to Rails 6.0 default config

* Switch to Rails 6.1 default config

* Do not include autoload paths in the load path

3 files changed, 8 insertions, 8 deletions

diff --git a/app/lib/delivery_failure_tracker.rb b/app/lib/delivery_failure_tracker.rb
index 25fa694d2..2cd6ef7ad 100644
--- a/app/lib/delivery_failure_tracker.rb
+++ b/app/lib/delivery_failure_tracker.rb
@@ -29,7 +29,7 @@ class DeliveryFailureTracker
 
   class << self
     def without_unavailable(urls)
-      unavailable_domains_map = Rails.cache.fetch('unavailable_domains') { UnavailableDomain.pluck(:domain).each_with_object({}) { |domain, hash| hash[domain] = true } }
+      unavailable_domains_map = Rails.cache.fetch('unavailable_domains') { UnavailableDomain.pluck(:domain).index_with(true) }
 
       urls.reject do |url|
         host = Addressable::URI.parse(url).normalized_host
diff --git a/app/lib/feed_manager.rb b/app/lib/feed_manager.rb
index 165338437..43aeecb35 100644
--- a/app/lib/feed_manager.rb
+++ b/app/lib/feed_manager.rb
@@ -533,12 +533,12 @@ class FeedManager
       arr
     end
 
-    crutches[:following]       = Follow.where(account_id: receiver_id, target_account_id: statuses.map(&:in_reply_to_account_id).compact).pluck(:target_account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
-    crutches[:hiding_reblogs]  = Follow.where(account_id: receiver_id, target_account_id: statuses.map { |s| s.account_id if s.reblog? }.compact, show_reblogs: false).pluck(:target_account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
-    crutches[:blocking]        = Block.where(account_id: receiver_id, target_account_id: check_for_blocks).pluck(:target_account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
-    crutches[:muting]          = Mute.where(account_id: receiver_id, target_account_id: check_for_blocks).pluck(:target_account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
-    crutches[:domain_blocking] = AccountDomainBlock.where(account_id: receiver_id, domain: statuses.map { |s| s.reblog&.account&.domain }.compact).pluck(:domain).each_with_object({}) { |domain, mapping| mapping[domain] = true }
-    crutches[:blocked_by]      = Block.where(target_account_id: receiver_id, account_id: statuses.map { |s| s.reblog&.account_id }.compact).pluck(:account_id).each_with_object({}) { |id, mapping| mapping[id] = true }
+    crutches[:following]       = Follow.where(account_id: receiver_id, target_account_id: statuses.map(&:in_reply_to_account_id).compact).pluck(:target_account_id).index_with(true)
+    crutches[:hiding_reblogs]  = Follow.where(account_id: receiver_id, target_account_id: statuses.map { |s| s.account_id if s.reblog? }.compact, show_reblogs: false).pluck(:target_account_id).index_with(true)
+    crutches[:blocking]        = Block.where(account_id: receiver_id, target_account_id: check_for_blocks).pluck(:target_account_id).index_with(true)
+    crutches[:muting]          = Mute.where(account_id: receiver_id, target_account_id: check_for_blocks).pluck(:target_account_id).index_with(true)
+    crutches[:domain_blocking] = AccountDomainBlock.where(account_id: receiver_id, domain: statuses.map { |s| s.reblog&.account&.domain }.compact).pluck(:domain).index_with(true)
+    crutches[:blocked_by]      = Block.where(target_account_id: receiver_id, account_id: statuses.map { |s| s.reblog&.account_id }.compact).pluck(:account_id).index_with(true)
 
     crutches
   end
diff --git a/app/lib/settings/scoped_settings.rb b/app/lib/settings/scoped_settings.rb
index acabf0c8e..1e18d6d46 100644
--- a/app/lib/settings/scoped_settings.rb
+++ b/app/lib/settings/scoped_settings.rb
@@ -63,7 +63,7 @@ module Settings
 
     class << self
       def default_settings
-        defaulting = DEFAULTING_TO_UNSCOPED.each_with_object({}) { |k, h| h[k] = Setting[k] }
+        defaulting = DEFAULTING_TO_UNSCOPED.index_with { |k| Setting[k] }
         Setting.default_settings.merge!(defaulting)
       end
     end