A few more gametests, update to Gradle 8.12

Okay, listen. I started writing a few more gametests (see #1682), and
then thought I'd do a cheeky Gradle update. However, that broke
vanilla-extract[^1], and also triggered a load of deprecation warnings,
and at that point it was too late to separate the too.

[^1]: 8975ed5a7b

projects/fabric/build.gradle.kts

@@ -31,10 +31,10 @@ fun addRemappedConfiguration(name: String) {
     }
     val capitalName = name.replaceFirstChar { it.titlecase(Locale.ROOT) }
     loom.addRemapConfiguration("mod$capitalName") {
-        onCompileClasspath.set(false)
-        onRuntimeClasspath.set(true)
-        sourceSet.set(ourSourceSet)
-        targetConfigurationName.set(name)
+        onCompileClasspath = false
+        onRuntimeClasspath = true
+        sourceSet = ourSourceSet
+        targetConfigurationName = name
     }
     configurations.create(name) {
         isCanBeConsumed = false
@@ -107,8 +107,8 @@ dependencies {
 }
 
 loom {
-    accessWidenerPath.set(project(":common").file("src/main/resources/computercraft.accesswidener"))
-    mixin.defaultRefmapName.set("computercraft.refmap.json")
+    accessWidenerPath = project(":common").file("src/main/resources/computercraft.accesswidener")
+    mixin.defaultRefmapName = "computercraft.refmap.json"
 
     mods {
         register("computercraft") {
@@ -285,7 +285,7 @@ tasks.register("checkClient") {
 }
 
 modPublishing {
-    output.set(tasks.remapJar)
+    output = tasks.remapJar
 }
 
 tasks.withType(GenerateModuleMetadata::class).configureEach { isEnabled = false }

projects/fabric/src/testMod/java/dan200/computercraft/gametest/core/TestMod.java

@@ -26,7 +26,7 @@ public class TestMod implements ModInitializer, ClientModInitializer {
         var phase = new ResourceLocation(ComputerCraftAPI.MOD_ID, "test_mod");
         ServerLifecycleEvents.SERVER_STARTED.addPhaseOrdering(Event.DEFAULT_PHASE, phase);
         ServerLifecycleEvents.SERVER_STARTED.register(phase, TestHooks::onServerStarted);
-        CommandRegistrationCallback.EVENT.register((dispatcher, registryAccess, environment) -> CCTestCommand.register(dispatcher));
+        CommandRegistrationCallback.EVENT.register((dispatcher, buildContext, environment) -> CCTestCommand.register(dispatcher, buildContext));
         PlayerBlockBreakEvents.BEFORE.register((level, player, pos, state, blockEntity) -> !TestHooks.onBeforeDestroyBlock(level, pos, state));
 
         TestHooks.loadTests(GameTestRegistry::register);