Nest some more namespaces

Did someone previously suggest that all namespace had been
nested?  Silly.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I22278c1caaeba8b47dc46fb2ed3078c20a11e190
diff --git a/y2023/vision/aprilrobotics.h b/y2023/vision/aprilrobotics.h
index 123f352..e11bfcc 100644
--- a/y2023/vision/aprilrobotics.h
+++ b/y2023/vision/aprilrobotics.h
@@ -21,8 +21,7 @@
 #include "frc971/vision/visualize_robot.h"
 #include "y2023/constants/constants_generated.h"
 
-namespace y2023 {
-namespace vision {
+namespace y2023::vision {
 
 class AprilRoboticsDetector {
  public:
@@ -97,5 +96,4 @@
   frc971::vision::VisualizeRobot vis_robot_;
 };
 
-}  // namespace vision
-}  // namespace y2023
+}  // namespace y2023::vision
diff --git a/y2023/vision/game_pieces.h b/y2023/vision/game_pieces.h
index 442d95c..45bf894 100644
--- a/y2023/vision/game_pieces.h
+++ b/y2023/vision/game_pieces.h
@@ -6,8 +6,7 @@
 #include "y2023/vision/game_pieces_generated.h"
 #include "y2023/vision/yolov5.h"
 
-namespace y2023 {
-namespace vision {
+namespace y2023::vision {
 
 using namespace frc971::vision;
 
@@ -23,6 +22,5 @@
   aos::Sender<GamePieces> game_pieces_sender_;
   std::unique_ptr<YOLOV5> model;
 };
-}  // namespace vision
-}  // namespace y2023
+}  // namespace y2023::vision
 #endif
diff --git a/y2023/vision/yolov5.h b/y2023/vision/yolov5.h
index 9853b4f..2d7f641 100644
--- a/y2023/vision/yolov5.h
+++ b/y2023/vision/yolov5.h
@@ -13,8 +13,7 @@
 #include <opencv2/imgcodecs.hpp>
 #include <opencv2/imgproc.hpp>
 
-namespace y2023 {
-namespace vision {
+namespace y2023::vision {
 
 struct Detection {
   cv::Rect box;
@@ -36,7 +35,6 @@
 
 std::unique_ptr<YOLOV5> MakeYOLOV5();
 
-}  // namespace vision
-}  // namespace y2023
+}  // namespace y2023::vision
 
 #endif  // Y2023_VISION_YOLOV5_H_