build: upgrade to C++23

Meson 1.1.1 and GCC-13 both support C++23 and a sufficient portion of
the standard has been implemented.  Upgrade the build to leverage it.

Change-Id: I35bca64638976c0e20346d78d46311a580245503
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/meson.build b/meson.build
index 073fe7a..74fc139 100644
--- a/meson.build
+++ b/meson.build
@@ -1,10 +1,10 @@
 project('phosphor-time-manager',
         'cpp',
          version: '0.1',
-         meson_version: '>=0.58.0',
+         meson_version: '>=1.1.1',
          default_options: [ 'warning_level=3',
                             'werror=true',
-                            'cpp_std=c++20',
+                            'cpp_std=c++23',
                             'buildtype=debugoptimized' ])
 
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