perf(opentelemetry): increase max batch size (#12488)

The max batch size for Opentelemetry was set to the default value: 1
the value actually refers to the number of spans in a batch, so we are
increasing the default value to 200 which corresponds to what the
default value used to be with the "old" queue implementation.

(cherry picked from commit c7cb900)

changelog/unreleased/kong/otel-increase-queue-max-batch-size.yml

@@ -0,0 +1,3 @@
+message: "**Opentelemetry**: increase queue max batch size to 200"
+type: performance
+scope: Plugin

kong/plugins/opentelemetry/schema.lua

@@ -44,7 +44,11 @@ return {
           },
         } },
         { resource_attributes = resource_attributes },
-        { queue = typedefs.queue },
+        { queue = typedefs.queue {
+          default = {
+            max_batch_size = 200,
+          },
+        } },
         { batch_span_count = { description = "The number of spans to be sent in a single batch.", type = "integer" } },
         { batch_flush_delay = { description = "The delay, in seconds, between two consecutive batches.", type = "integer" } },
         { connect_timeout = typedefs.timeout { default = 1000 } },