Disconnect the pool during failover and fallback.

lib/active_record/connection_adapters/postgresql_fallback_adapter.rb

@@ -98,8 +98,7 @@ class PostgreSQLFallbackHandler
   end
 
   def clear_connections
-    ActiveRecord::Base.clear_active_connections!
-    ActiveRecord::Base.clear_all_connections!
+    ActiveRecord::Base.connection_pool.disconnect
   end
 
   private

spec/components/active_record/connection_adapters/postgresql_fallback_adapter_spec.rb

@@ -27,7 +27,6 @@ describe ActiveRecord::ConnectionHandling do
   let(:postgresql_fallback_handler) { PostgreSQLFallbackHandler.instance }
 
   before do
-    skip("Figure out why this test leaks connections")
     postgresql_fallback_handler.initialized = true
 
     ['default', multisite_db].each do |db|