Fix RSpec/AnyInstance cop (#27810)

spec/lib/request_spec.rb

@@ -64,8 +64,11 @@ describe Request do
       end
 
       it 'closes underlying connection' do
-        expect_any_instance_of(HTTP::Client).to receive(:close)
+        allow(subject.send(:http_client)).to receive(:close)
+
         expect { |block| subject.perform(&block) }.to yield_control
+
+        expect(subject.send(:http_client)).to have_received(:close)
       end
 
       it 'returns response which implements body_with_limit' do