Allow building with boost 1.87

Boost for whatever reason added nodiscard on boost::asio::spawn.  Long
term someone likely needs to move this coroutine stuff over to c++20
coroutines, but for now, put in maybe_unused where appropriate.

Change-Id: I72c2039a2bb1e6198a543f89a1820ed3cb78c9df
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/ipmid-new.cpp b/ipmid-new.cpp
index ea833ff..1e85a0d 100644
--- a/ipmid-new.cpp
+++ b/ipmid-new.cpp
@@ -20,6 +20,7 @@
 #include <dlfcn.h>
 
 #include <boost/algorithm/string.hpp>
+#include <boost/asio/detached.hpp>
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/spawn.hpp>
 #include <host-cmd-manager.hpp>
@@ -765,7 +766,7 @@
 {
     // make a copy so the next two moves don't wreak havoc on the stack
     sdbusplus::message_t b{m};
-    (void)boost::asio::spawn(
+    boost::asio::spawn(
         *getIoContext(),
         [b = std::move(b)](boost::asio::yield_context yield) {
             sdbusplus::message_t m{std::move(b)};
@@ -802,7 +803,7 @@
                     netFn, "CMD", lg2::hex, cmd);
             }
         },
-        {});
+        boost::asio::detached);
 }
 
 #endif /* ALLOW_DEPRECATED_API */