Add $match stage to filter for query operations in the $currentOp task of the DSI workloads/query-integration/currentOp performance test. The task should also add an assertion to check that we actually found query operations at a certain threshold in the test, i.e half way through the allotted run time we must assume $currentOp reported a query operation at some point.

https://github.com/10gen/dsi/blob/69d4e4ef2914fcd8c6461f2641d5f120ee5c712f/workloads/query-integration/currentOp/src/currentOp_workload.py#L148

The assertion could look something like:

pipeline = [
        {"$currentOp": {}},
        {"$match": {"op": "query", "active": True}}  # adjust predicate as needed
    ]
    cursor = self.admin_database.aggregate(pipeline)
    ops = list(cursor)    # Only assert after a warmup of 10 runs.
    if self.run_count > 10:
        assert ops, "No active query operations found."