No, there is no limit to the number of versions you can create.
Adding new versions is possible by clicking the “add a new version” button right below the last version of your trigger and a new box will appear.
Keep in mind though that depending on your server and how your site is built, a large number of versions may affect your site it two ways:
If you have a large number of different versions, we highly recommend using our CSV (bulks) extension instead of a dynamic trigger.