Fix CommandAPI loading on old versions (tested 1.19)

This was a similar issue to what was brought up here: #594 (comment). It seems that having `NMS_1_21_R1::new` as a method reference still loads the `NMS_1_21_R1` class enough that Java gets mad. On 1.19, trying to load the CommandAPI gives `java.lang.VerifyError: Bad type on operand stack - Type 'net/minecraft/commands/CommandBuildContext' (current frame, stack[1]) is not assignable to 'net/minecraft/core/HolderLookup$a'` with the stacktrace going through that line.

Moving all references to the `NMS_1_21_R1` class into the if statements allowed loading on 1.19 as expected. That does mean the slight inconvenience of having to specify and update the latest NMS object in two place.

commandapi-platforms/commandapi-bukkit/commandapi-bukkit-vh/src/main/java/dev/jorel/commandapi/CommandAPIVersionHandler.java

@@ -24,8 +24,6 @@
 import dev.jorel.commandapi.nms.*;
 import org.bukkit.Bukkit;
 
-import java.util.function.Supplier;
-
 /**
  * This file handles the NMS version to be loaded. The CommandAPIVersionHandler
  * file within the commandapi-core module is NOT used at compile time. Instead,
@@ -52,9 +50,8 @@ public interface CommandAPIVersionHandler {
  */
  static LoadContext getPlatform() {
  String latestMajorVersion = "21"; // Change this for Minecraft's major update
- Supplier<CommandAPIPlatform<?, ?, ?>> latestNMS = NMS_1_21_R1::new;
  if (CommandAPI.getConfiguration().shouldUseLatestNMSVersion()) {
- return new LoadContext(latestNMS.get(), () -> {
+ return new LoadContext(new NMS_1_21_R1(), () -> {
  CommandAPI.logWarning("Loading the CommandAPI with the latest and potentially incompatible NMS implementation.");
  CommandAPI.logWarning("While you may find success with this, further updates might be necessary to fully support the version you are using.");
  });
@@ -83,7 +80,7 @@ static LoadContext getPlatform() {
  if (CommandAPI.getConfiguration().shouldBeLenientForMinorVersions()) {
  String currentMajorVersion = version.split("\\.")[1];
  if (latestMajorVersion.equals(currentMajorVersion)) {
- return new LoadContext(latestNMS.get(), () -> {
+ return new LoadContext(new NMS_1_21_R1(), () -> {
  CommandAPI.logWarning("Loading the CommandAPI with a potentially incompatible NMS implementation.");
  CommandAPI.logWarning("While you may find success with this, further updates might be necessary to fully support the version you are using.");
  });