use std::move_only_function

C++23 has a replacement for function2 in std::move_only_function.
Leverage that and remove the extra dependency.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I69fa59627b91fc1f640f7a688926bed7f138ca19
diff --git a/tools/meson.build b/tools/meson.build
index 58fff65..826d04c 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -5,8 +5,7 @@
   dependency('pciaccess', fallback: ['pciaccess', 'dep_pciaccess']),
   dependency('stdplus', fallback: ['stdplus', 'stdplus_dep']),
   blobs_dep,
-  sys_dep,
-  function2_dep]
+  sys_dep]
 
 updater_lib = static_library(
   'updater_lib',