boost version 1.86 support

Added fix for boost::asio::spawn overload issue reported similar
to chriskohlhoff/asio#1524. This error reported by CI build during
boost version bump.

Error details

'''
 ../example/asio-example.cpp:375:23:
  error: call of overloaded ‘spawn(boost::asio::io_context&, client()::<lambda(boost::asio::yield_context)>)’ is ambiguous
  375 |     boost::asio::spawn(io, [conn](boost::asio::yield_context yield) {
      |     ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  376 |         do_start_async_method_call_one(conn, yield);
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  377 |     });
      |     ~~
In file included from /usr/local/include/boost/asio/spawn.hpp:871,
                 from ../example/asio-example.cpp:2:
'''

Proposed fix is to explicitly specify the completion token.

Tested: verified build

Change-Id: I5ec16f8f33c617a6abc823abf75b765c0d031141
Signed-off-by: Jayanth Othayoth <ojayanth@gmail.com>
diff --git a/example/asio-example.cpp b/example/asio-example.cpp
index f5f0176..145e87a 100644
--- a/example/asio-example.cpp
+++ b/example/asio-example.cpp
@@ -1,3 +1,4 @@
+#include <boost/asio/detached.hpp>
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/spawn.hpp>
 #include <sdbusplus/asio/connection.hpp>
@@ -372,15 +373,24 @@
 
     // set up a client to make an async call to the server
     // using coroutines (userspace cooperative multitasking)
-    boost::asio::spawn(io, [conn](boost::asio::yield_context yield) {
-        do_start_async_method_call_one(conn, yield);
-    });
-    boost::asio::spawn(io, [conn](boost::asio::yield_context yield) {
-        do_start_async_ipmi_call(conn, yield);
-    });
-    boost::asio::spawn(io, [conn](boost::asio::yield_context yield) {
-        do_start_async_to_yield(conn, yield);
-    });
+    boost::asio::spawn(
+        io,
+        [conn](boost::asio::yield_context yield) {
+            do_start_async_method_call_one(conn, yield);
+        },
+        boost::asio::detached);
+    boost::asio::spawn(
+        io,
+        [conn](boost::asio::yield_context yield) {
+            do_start_async_ipmi_call(conn, yield);
+        },
+        boost::asio::detached);
+    boost::asio::spawn(
+        io,
+        [conn](boost::asio::yield_context yield) {
+            do_start_async_to_yield(conn, yield);
+        },
+        boost::asio::detached);
 
     conn->async_method_call(
         [](boost::system::error_code ec, int32_t testValue) {