Fix test-related issues (#17888)

* Remove obsolete RSS::Serializer test

Since #17828, RSS::Serializer no longer has specific code for deleted statuses,
but it is never called on deleted statuses anyway.

* Rename erroneously-named test files

* Fix failing test

* Fix test deprecation warnings

* Update CircleCI Ruby orb

1.4.0 has a bug that does not match all the test files due to incorrect
globbing

spec/services/suspend_account_service_spec.rb

@@ -5,9 +5,7 @@ RSpec.describe SuspendAccountService, type: :service do
     let!(:local_follower) { Fabricate(:user, current_sign_in_at: 1.hour.ago).account }
     let!(:list)           { Fabricate(:list, account: local_follower) }
 
-    subject do
-      -> { described_class.new.call(account) }
-    end
+    subject { described_class.new.call(account) }
 
     before do
       allow(FeedManager.instance).to receive(:unmerge_from_home).and_return(nil)
@@ -18,13 +16,13 @@ RSpec.describe SuspendAccountService, type: :service do
     end
 
     it "unmerges from local followers' feeds" do
-      subject.call
+      subject
       expect(FeedManager.instance).to have_received(:unmerge_from_home).with(account, local_follower)
       expect(FeedManager.instance).to have_received(:unmerge_from_list).with(account, list)
     end
 
     it 'marks account as suspended' do
-      is_expected.to change { account.suspended? }.from(false).to(true)
+      expect { subject }.to change { account.suspended? }.from(false).to(true)
     end
   end
 
@@ -51,7 +49,7 @@ RSpec.describe SuspendAccountService, type: :service do
       end
 
       it 'sends an update actor to followers and reporters' do
-        subject.call
+        subject
         expect(a_request(:post, remote_follower.inbox_url).with { |req| match_update_actor_request(req, account) }).to have_been_made.once
         expect(a_request(:post, remote_reporter.inbox_url).with { |req| match_update_actor_request(req, account) }).to have_been_made.once
       end
@@ -77,7 +75,7 @@ RSpec.describe SuspendAccountService, type: :service do
       end
 
       it 'sends a reject follow' do
-        subject.call
+        subject
         expect(a_request(:post, account.inbox_url).with { |req| match_reject_follow_request(req, account, local_followee) }).to have_been_made.once
       end
     end