Revert partial aggregate opt in (#1721)

Summary: Revert partial aggregate opt in

This change reverts the partial aggregate opt in from
2645963. During the testing of
0.14.7-pre-main.0, I noticed that the flame graphs generated were
lacking the typical towers seen.

<img width="1728" alt="Java flame graph on pre-release"
src="https://github.com/pixie-io/pixie/assets/5855593/5e1f15f0-97ce-4263-a418-9986f675fa55">
<img width="1679" alt="flame graph on pre-release"
src="https://github.com/pixie-io/pixie/assets/5855593/f2b7d988-471c-48e0-bed1-339896574940">

Relevant Issues: #1440

Type of change: /kind bug

Test Plan: `skaffold`ed the changes and verified that the flame graph
looks correct now (as seen below)
<img width="1718" alt="flame graph with partial agg revert"
src="https://github.com/pixie-io/pixie/assets/5855593/f6c947fe-1930-4bc5-bdb9-89f33cf0e19a">

Signed-off-by: Dom Del Nano <[email protected]>

src/carnot/planner/distributed/coordinator/coordinator.cc

@@ -179,7 +179,7 @@ StatusOr<SchemaToAgentsMap> LoadSchemaMap(
 
 StatusOr<std::unique_ptr<DistributedPlan>> CoordinatorImpl::CoordinateImpl(const IR* logical_plan) {
   PX_ASSIGN_OR_RETURN(std::unique_ptr<Splitter> splitter,
-                      Splitter::Create(compiler_state_, /* support_partial_agg */ true));
+                      Splitter::Create(compiler_state_, /* support_partial_agg */ false));
   PX_ASSIGN_OR_RETURN(std::unique_ptr<BlockingSplitPlan> split_plan,
                       splitter->SplitKelvinAndAgents(logical_plan));
   auto distributed_plan = std::make_unique<DistributedPlan>();