How can I delete a file from inside a task?

Running it as a separate task worked. However, I don’t want to have to remember to create a separate delete task every time I want to create an installer task.

tasks.register<Delete>("deleteJpackageImage") {
    delete(files("${project.buildDir}/jpackageAppImage"))
}

I’d really like to be able to just have the Installer task work without any outside logic. Also, I’d like to understand why delete inside of my task is failing so that I can have a better understanding of Gradle.