fix(nodestore): keep the rotation-phase code building with telemetry off

RotationPhase reads owner_ and stage_ only inside the metric macro in its
destructor. With -DXRPL_ENABLE_TELEMETRY=0 that macro expands to nothing,
so clang reports both as unused private fields and -Werror makes it an
error. Mark them [[maybe_unused]].

The rotation-phase label constants reach RotationPhase as ordinary
constructor arguments, not as macro arguments, so MetricNames.h is needed
in both builds and no longer sits under the telemetry guard.

src/xrpld/app/misc/SHAMapStoreImp.cpp

@@ -29,12 +29,10 @@
 #include <xrpl/server/State.h>
 #include <xrpl/shamap/SHAMapMissingNode.h>
 #include <xrpl/shamap/SHAMapTreeNode.h>
-#include <xrpl/telemetry/MetricMacros.h>
-#ifdef XRPL_ENABLE_TELEMETRY
-// The metric-name constants are named only as macro arguments, which the
-// macros drop when telemetry is compiled out.
+// MetricNames.h is unguarded because the rotation-phase label constants are
+// passed to RotationPhase as ordinary constructor arguments, in both builds.
+#include <xrpl/telemetry/MetricMacros.h>  // IWYU pragma: keep
 #include <xrpl/telemetry/MetricNames.h>
-#endif
 #include <xrpl/telemetry/SpanGuard.h>
 #include <xrpl/telemetry/SpanNames.h>
 

src/xrpld/app/misc/SHAMapStoreImp.h

@@ -253,8 +253,10 @@ private:
         }
 
     private:
-        SHAMapStoreImp& owner_;
-        char const* stage_;
+        // Read only inside the metric macro in the destructor, so a
+        // -DXRPL_ENABLE_TELEMETRY=0 build sees no use at all.
+        [[maybe_unused]] SHAMapStoreImp& owner_;
+        [[maybe_unused]] char const* stage_;
         std::chrono::steady_clock::time_point start_ = std::chrono::steady_clock::now();
         telemetry::ScopedSpanGuard span_;
     };