Removes some unused imports and variables

src/main/java/net/knarcraft/bookswithoutborders/command/CommandDecrypt.java

@@ -17,12 +17,6 @@ import java.io.File;
  */
 public class CommandDecrypt implements CommandExecutor {
 
-    private final BooksWithoutBorders booksWithoutBorders;
-
-    public CommandDecrypt(BooksWithoutBorders booksWithoutBorders) {
-        this.booksWithoutBorders = booksWithoutBorders;
-    }
-
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
         if (!(sender instanceof Player player)) {

src/main/java/net/knarcraft/bookswithoutborders/command/CommandEncrypt.java

@@ -16,12 +16,6 @@ import org.bukkit.inventory.meta.BookMeta;
  */
 public class CommandEncrypt implements CommandExecutor {
 
-    private final BooksWithoutBorders booksWithoutBorders;
-
-    public CommandEncrypt(BooksWithoutBorders booksWithoutBorders) {
-        this.booksWithoutBorders = booksWithoutBorders;
-    }
-
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
         if (performPreChecks(sender, args, 1, "You must specify a key to encrypt a book!") == null) {

src/main/java/net/knarcraft/bookswithoutborders/command/CommandGroupEncrypt.java

@@ -15,10 +15,6 @@ import java.util.List;
  */
 public class CommandGroupEncrypt extends CommandEncrypt implements CommandExecutor {
 
-    public CommandGroupEncrypt(BooksWithoutBorders booksWithoutBorders) {
-        super(booksWithoutBorders);
-    }
-
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
         BookMeta bookMetadata = performPreChecks(sender, args, 2,