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/dbus-sdr/storagecommands.cpp b/dbus-sdr/storagecommands.cpp
index d169367..3d16344 100644
--- a/dbus-sdr/storagecommands.cpp
+++ b/dbus-sdr/storagecommands.cpp
@@ -20,6 +20,7 @@
 #include "selutility.hpp"
 
 #include <boost/algorithm/string.hpp>
+#include <boost/asio/detached.hpp>
 #include <boost/container/flat_map.hpp>
 #include <boost/process.hpp>
 #include <ipmid/api.hpp>
@@ -346,11 +347,12 @@
         });
 
     // call once to populate
-    (void)boost::asio::spawn(*getIoContext(),
-                             [](boost::asio::yield_context yield) {
-                                 replaceCacheFru(getSdBus(), yield);
-                             },
-                             {});
+    boost::asio::spawn(
+        *getIoContext(),
+        [](boost::asio::yield_context yield) {
+            replaceCacheFru(getSdBus(), yield);
+        },
+        boost::asio::detached);
 }
 
 /** @brief implements the read FRU data command
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 */
diff --git a/meson.build b/meson.build
index aa6da2a..7e8795a 100644
--- a/meson.build
+++ b/meson.build
@@ -126,7 +126,7 @@
 
 # Dependencies
 
-boost = dependency('boost', modules: ['coroutine'], required: false)
+boost = dependency('boost', modules: ['context', 'coroutine'], required: false)
 
 if not boost.found()
     cmake = import('cmake')