[skip ci] Fix typo in developer guide (#11551)

Signed-off-by: NBinbin Lv <binbin.lv@zilliz.com>

docs/developer_guides/chap05_proxy.md

@@ -567,7 +567,7 @@ func NewTaskScheduler(ctx context.Context, idAllocator *allocator.IDAllocator, t
 	factory msgstream.Factory) (*TaskScheduler, error)
 ```
 
-_scheduleDdTask()_ selects tasks in a FIFO manner, thus time order is garanteed.
+_scheduleDdTask()_ selects tasks in a FIFO manner, thus time order is guaranteed.
 
 The policy of _scheduleDmTask()_ should target on throughput, not tasks' time order. Note that the time order of the tasks' execution will later be garanteed by the timestamp & time tick mechanism.