Add a config option to limit the amount of custom pings an user can have

config/src/main/groovy/net/neoforged/camelot/config/module/CustomPings.groovy

@@ -12,4 +12,10 @@ class CustomPings extends ModuleConfiguration {
      * The channel in which to create ping private threads if a member does not have DMs enabled.
      */
     long pingThreadsChannel
+
+    /**
+     * The maximum amount of custom pings an user can have.
+     * {@code -1} means indefinite
+     */
+    int limit = 100
 }

src/main/java/net/neoforged/camelot/commands/utility/CustomPingsCommand.java

@@ -18,6 +18,7 @@
 import net.neoforged.camelot.commands.PaginatableCommand;
 import net.neoforged.camelot.db.schemas.Ping;
 import net.neoforged.camelot.db.transactionals.PingsDAO;
+import net.neoforged.camelot.module.CustomPingsModule;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
@@ -66,6 +67,16 @@ protected void execute(SlashCommandEvent event) {
                 return;
             }
 
+            final var pingAmount = Database.pings().withExtension(PingsDAO.class,
+                    db -> db.getAllPingsOf(event.getUser().getIdLong(), event.getGuild().getIdLong()))
+                    .size();
+
+            final var config = BotMain.getModule(CustomPingsModule.class).config();
+            if (config.getLimit() >= 0 && pingAmount >= config.getLimit()) {
+                event.reply(STR."You have already reached your limit of **\{config.getLimit()}** custom pings.").setEphemeral(true).queue();
+                return;
+            }
+
             Database.pings().useExtension(PingsDAO.class, db -> db.insert(
                     event.getGuild().getIdLong(), event.getUser().getIdLong(),
                     regex, event.getOption("message", "", OptionMapping::getAsString)