Rust intropsection: disable max depth rule

This protection against introspection queries generating huge responses
was added recently in graphql-js graphql/graphql-js#4118
and ported to rust apollographql/apollo-rs#904,
but is not yet present in the graphql-js version used by router-bridge.

This disables it for now from Rust introspection, in order to match
the current state of JS introspection.

Adding this rule (in both implementations) can be revisited separately.
In particular: the depth limit is hard-coded to 3. Is that the right number?
Should it be configurable? Is the rule checking the right set of fields?

Author: SimonSapin

apollo-router/src/query_planner/bridge_query_planner.rs

@@ -559,12 +559,6 @@ impl BridgeQueryPlanner {
     ) -> Result<graphql::Response, QueryPlannerError> {
         let schema = self.schema.api_schema();
         let operation = doc.get_operation(key.operation_name.as_deref())?;
-        apollo_compiler::execution::check_introspection_max_depth(&doc.executable, operation)
-            .map_err(|_e| {
-                QueryPlannerError::Introspection(IntrospectionError {
-                    message: Some("Maximum introspection depth exceeded".to_owned()),
-                })
-            })?;
         let variable_values = Default::default();
         let variable_values =
             apollo_compiler::execution::coerce_variable_values(schema, operation, &variable_values)