build: update to C++20

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I2708fb4ccfc75e4f857603ede96a93011eaaae08
diff --git a/meson.build b/meson.build
index 8fcb47e..6b21531 100644
--- a/meson.build
+++ b/meson.build
@@ -3,8 +3,9 @@
     'cpp',
     version: '1.0',
     default_options: [
-        'cpp_std=c++17',
+        'cpp_std=c++20',
     ],
+    meson_version: '>=0.57.0',
 )
 
 cpp = meson.get_compiler('cpp')