Deprecate ChatColor (#9069)

All API that uses it is deprecated

patches/server/Paper-config-files.patch

@@ -3261,6 +3261,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +        });
 +    }
 +
++    @SuppressWarnings("deprecation") // valid use to convert legacy string to mini-message in legacy migration
 +    private static String miniMessage(final String input) {
 +        return MiniMessage.miniMessage().serialize(LegacyComponentSerializer.legacySection().deserialize(ChatColor.translateAlternateColorCodes('&', input)));
 +    }