src/msg/Policy: explicitly include <map> for std::map usage

The Seastar update brought in a newer toolchain, which stopped pulling in <map> indirectly through other headers.
That exposed missing includes in Policy.h, where std::map was used but <map> wasn’t explicitly included.

Signed-off-by: Aishwarya Mathuria <[email protected]>

Author: amathuria

src/msg/Policy.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include "include/ceph_features.h"
+#include <map>
 
 namespace ceph::net {