Incompatible with mongodb >= 5.1 due to usage of deprecated OP_QUERY commands

[whophil]

txmongo cannot interact with mongo DB servers with version >= 5.1, due to its usage of the OP_QUERY command.

The OP_QUERY command was deprecated in MongoDB 5.1, according to
https://www.mongodb.com/docs/manual/reference/mongodb-wire-protocol/#ref-op-query-footnote-id4

[IlyaSkriblovsky]

There is already a PR on this: #262
But it lacks testing and reviews :( I ceased to use TxMongo in production by myself so it would be great if somebody could test it.

[whophil]

Thanks @IlyaSkriblovsky ! Sorry I didn't see that.

I also don't use txmongo in production, I'm just poking around here to get CI on a downstream project to work.