MONGOID-5810 make sure we don't leak internal state via as_document (backport to 8.0-stable) #3790

Job	Run time
ruby-3.1 driver-current mongodb-5.0 server	10m 59s
ruby-3.1 driver-current mongodb-5.0 replica_set	12m 52s
ruby-3.0 driver-current mongodb-5.0 server	10m 25s
ruby-3.0 driver-current mongodb-5.0 replica_set	13m 15s
jruby-9.3 driver-current mongodb-5.0 replica_set	21m 16s
ruby-2.7 driver-current mongodb-4.4 server	10m 42s
ruby-2.7 driver-current mongodb-4.4 replica_set	12m 20s
ruby-2.6 driver-current mongodb-4.0 server	1s
ruby-2.6 driver-current mongodb-4.0 replica_set	1s
ruby-2.6 driver-current mongodb-3.6 server	1s
ruby-2.6 driver-current mongodb-3.6 replica_set	1s
ruby-3.1 driver-master mongodb-5.0 replica_set	12m 45s
ruby-3.0 driver-stable mongodb-5.0 replica_set	12m 5s
ruby-2.6 driver-oldstable mongodb-4.0 replica_set	1s
ruby-2.6 driver-min mongodb-4.0 replica_set	1s
ruby-2.6 driver-min mongodb-3.6 server	1s
ruby-3.1 driver-current mongodb-5.0 server	10m 41s
ruby-3.1 driver-current mongodb-5.0 server	10m 29s
ruby-3.0 driver-current mongodb-5.0 server	10m 32s
ruby-3.0 driver-current mongodb-5.0 server	10m 17s
ruby-3.0 driver-current mongodb-5.0 server	10m 23s
ruby-2.7 driver-current mongodb-4.0 server	1s
ruby-2.6 driver-current mongodb-4.4 server	10m 16s
ruby-2.6 driver-current mongodb-4.2 server	1s
ruby-2.6 driver-current mongodb-4.2 server	1s
ruby-2.7 driver-current mongodb-5.0 server	10m 29s
jruby-9.3 driver-current mongodb-5.0 server	18m 45s
	3h 28m 41s

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