metropolis/node/core/minit: update year in copyright header

This updates the copyright line to include 2023.

Change-Id: I8442cb10d369ee1a13485f601242fee65c210ede
Reviewed-on: https://review.monogon.dev/c/monogon/+/1725
Vouch-Run-CI: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/metropolis/node/core/minit/main.c b/metropolis/node/core/minit/main.c
index d92f7ed..4ca9337 100644
--- a/metropolis/node/core/minit/main.c
+++ b/metropolis/node/core/minit/main.c
@@ -82,7 +82,7 @@
     cprintf(
         "\n"
         "  Metropolis Cluster Operating System\n"
-        "  Copyright 2020-2022 The Monogon Project Authors\n"
+        "  Copyright 2020-2023 The Monogon Project Authors\n"
         "\n"
     );