Replace Collections methods with {List,Map,Set}.of

The two implementations aren't entirely compatible - the implementation
returned by .of will throw an NPE on .contains(null), whereas the
Collections implementations just return false. However, we try to avoid
passing null to collections methods, so this should be safe.

There's no strong reason to do this, but it helps make the code a little
more consistent

projects/common/src/test/java/dan200/computercraft/shared/network/server/UploadFileMessageTest.java

@@ -16,7 +16,6 @@ import org.hamcrest.Matcher;
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -110,7 +109,7 @@ public class UploadFileMessageTest {
     @Provide
     Arbitrary<FileUpload> fileUpload() {
         return Combinators.combine(
-            Arbitraries.oneOf(Arrays.asList(
+            Arbitraries.oneOf(List.of(
                 // 1.16 doesn't correctly handle unicode file names. We'll be generous in our tests here.
                 Arbitraries.strings().ofMinLength(1).ascii().ofMaxLength(MAX_FILE_NAME),
                 Arbitraries.strings().ofMinLength(1).ofMaxLength(MAX_FILE_NAME / 4)