Nest all namespaces

The compiler supports this now.  We can type less going forward.
No functional changes.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I29d6fa4f9aacc0e381f1a7637294db0392466995
diff --git a/y2022/constants.cc b/y2022/constants.cc
index 04ca14c..7ad6213 100644
--- a/y2022/constants.cc
+++ b/y2022/constants.cc
@@ -19,8 +19,7 @@
 #include "y2022/control_loops/superstructure/intake/integral_intake_plant.h"
 #include "y2022/control_loops/superstructure/turret/integral_turret_plant.h"
 
-namespace y2022 {
-namespace constants {
+namespace y2022::constants {
 
 const int Values::kZeroingSampleSize;
 
@@ -412,5 +411,4 @@
 
 Values MakeValues() { return MakeValues(aos::network::GetTeamNumber()); }
 
-}  // namespace constants
-}  // namespace y2022
+}  // namespace y2022::constants