Update ViaVersion api usage (#4386)

- Switch to fluent accessor, since the getter was removed after being deprecated for 3 years

bootstrap/spigot/src/main/java/org/geysermc/geyser/platform/spigot/GeyserSpigotInjector.java

@@ -150,7 +150,7 @@ public class GeyserSpigotInjector extends GeyserInjector {
                 childHandler = (ChannelInitializer<Channel>) childHandlerField.get(handler);
                 // ViaVersion non-Paper-injector workaround so we aren't double-injecting
                 if (isViaVersion && childHandler instanceof BukkitChannelInitializer) {
-                    childHandler = ((BukkitChannelInitializer) childHandler).getOriginal();
+                    childHandler = ((BukkitChannelInitializer) childHandler).original();
                 }
                 break;
             } catch (Exception e) {

gradle/libs.versions.toml

@@ -23,7 +23,7 @@ log4j = "2.20.0"
 jline = "3.21.0"
 terminalconsoleappender = "1.2.0"
 folia = "1.19.4-R0.1-SNAPSHOT"
-viaversion = "4.0.0"
+viaversion = "4.9.2"
 adapters = "1.11-SNAPSHOT"
 commodore = "2.2"
 bungeecord = "a7c6ede"