fix: Mock server player connection

src/test/java/io/github/opencubicchunks/cubicchunks/mixin/test/common/server/MixinServerPlayerTest.java

@@ -0,0 +1,14 @@
+package io.github.opencubicchunks.cubicchunks.mixin.test.common.server;
+
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.network.ServerGamePacketListenerImpl;
+import org.mockito.Mockito;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(ServerPlayer.class)
+public class MixinServerPlayerTest {
+    @Shadow
+    @SuppressWarnings("unused")
+    public ServerGamePacketListenerImpl connection = Mockito.mock();
+}

src/test/java/io/github/opencubicchunks/cubicchunks/mixin/test/common/server/package-info.java

@@ -0,0 +1,7 @@
+@ParametersAreNonnullByDefault
+@MethodsReturnNonnullByDefault
+package io.github.opencubicchunks.cubicchunks.mixin.test.common.server;
+
+import javax.annotation.ParametersAreNonnullByDefault;
+
+import io.github.opencubicchunks.cc_core.annotation.MethodsReturnNonnullByDefault;

src/test/java/io/github/opencubicchunks/cubicchunks/test/server/level/TestServerPlayer.java

@@ -28,7 +28,7 @@ private ServerPlayer setupServerPlayer(ServerLevel serverLevel) {
         return new ServerPlayer(mock(RETURNS_DEEP_STUBS), serverLevel, mock(RETURNS_DEEP_STUBS), mock(RETURNS_DEEP_STUBS));
     }
 
-    // TODO: Stub. This test needs a network connection to work.
+    // TODO: Stub. Test fails.
     @Disabled @Test public void testTeleportToVanilla() throws Exception {
         try (CloseableReference<ServerLevel> serverLevelReference = setupServerLevel()) {
             ServerPlayer player = setupServerPlayer(serverLevelReference.value());