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/y2023_bot3/control_loops/drivetrain/drivetrain_base.cc b/y2023_bot3/control_loops/drivetrain/drivetrain_base.cc
index 5b30097..481cab0 100644
--- a/y2023_bot3/control_loops/drivetrain/drivetrain_base.cc
+++ b/y2023_bot3/control_loops/drivetrain/drivetrain_base.cc
@@ -15,9 +15,7 @@
 
 namespace chrono = ::std::chrono;
 
-namespace y2023_bot3 {
-namespace control_loops {
-namespace drivetrain {
+namespace y2023_bot3::control_loops::drivetrain {
 
 using ::frc971::constants::ShifterHallEffect;
 
@@ -85,6 +83,4 @@
   return kDrivetrainConfig;
 };
 
-}  // namespace drivetrain
-}  // namespace control_loops
-}  // namespace y2023_bot3
+}  // namespace y2023_bot3::control_loops::drivetrain
diff --git a/y2023_bot3/control_loops/superstructure/superstructure.cc b/y2023_bot3/control_loops/superstructure/superstructure.cc
index e77245e..b730ffa 100644
--- a/y2023_bot3/control_loops/superstructure/superstructure.cc
+++ b/y2023_bot3/control_loops/superstructure/superstructure.cc
@@ -9,9 +9,7 @@
 DEFINE_bool(ignore_distance, false,
             "If true, ignore distance when shooting and obay joystick_reader");
 
-namespace y2023_bot3 {
-namespace control_loops {
-namespace superstructure {
+namespace y2023_bot3::control_loops::superstructure {
 
 using ::aos::monotonic_clock;
 
@@ -51,6 +49,4 @@
   (void)status->Send(status_builder.Finish());
 }
 
-}  // namespace superstructure
-}  // namespace control_loops
-}  // namespace y2023_bot3
+}  // namespace y2023_bot3::control_loops::superstructure
diff --git a/y2023_bot3/control_loops/superstructure/superstructure_lib_test.cc b/y2023_bot3/control_loops/superstructure/superstructure_lib_test.cc
index 370ec17..d9c9d15 100644
--- a/y2023_bot3/control_loops/superstructure/superstructure_lib_test.cc
+++ b/y2023_bot3/control_loops/superstructure/superstructure_lib_test.cc
@@ -16,10 +16,7 @@
 DEFINE_string(output_folder, "",
               "If set, logs all channels to the provided logfile.");
 
-namespace y2023_bot3 {
-namespace control_loops {
-namespace superstructure {
-namespace testing {
+namespace y2023_bot3::control_loops::superstructure::testing {
 namespace {}  // namespace
 namespace chrono = std::chrono;
 
@@ -260,7 +257,4 @@
   VerifyNearGoal();
 }
 
-}  // namespace testing
-}  // namespace superstructure
-}  // namespace control_loops
-}  // namespace y2023_bot3
+}  // namespace y2023_bot3::control_loops::superstructure::testing