Prevent any and all attempts to access GitHub URLs

[gpettey-ercot]

I need an option to stop the plugin from making any attempt at all to access the internet on its own. I do not want it to "cache" anything; I know what Helm version I'm using, I supply the download URL to the plugin, and I neither need nor want it trying to access any public internet URLs for anything.

I am running behind a firewall, and the error printed is "org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal io.kokuwa.maven:helm-maven-plugin:6.17.0:push (deploy) on project [redacted]: Failed to get helm version"

Related to #386