Has anyone opted to install a VPN client as a GitHub action (example one & two) as an alternative to running self-hosted runners? Is there a downside to running a VPN client for use cases where you just need access to internal resources/endpoints behind a VPN?

I have done it with tailscale, but not as an alternative to self-hosted it was bc it was the only way to access a server that was not control by us. I will tell you it's hard since the headless version is annoying to work with and on MacOs action was a pain to setup. So I will recommend self-hosted when possible.

I think it is an interesting solution

So I was using MacOs images and at the time this actions did not support MacOs (it looks like it dose now) so what I did is use a the docker version of it and then send what I need it throw that tunnel, I also had to do this with another client but they used tailgate and it was the same or worst to setup haha