Update year (#350)

Author: vonzshik

docfx.json

@@ -74,7 +74,7 @@
     "xrefService": [ "https://xref.docs.microsoft.com/query?uid={uid}" ],
     "globalMetadata": {
       "_appTitle": "Npgsql Documentation",
-      "_appFooter": "© Copyright 2023 The Npgsql Development Team",
+      "_appFooter": "© Copyright 2024 The Npgsql Development Team",
       "_enableSearch": true,
       "_gitContribute": {
         "branch": "main"