Feature request: Forward GPG keys when connecting with VS Code or JetBrains

When using VS Code, we're unable to make verified commits due to the gpg key not being present. It would be nice to not need to copy gpg keys on to the server. I've been able to get around this by running `coder ssh -AG` in a terminal and keeping that alive while I do my work. Then I can commit from VS Code using my gpg key. It would be nice to not need this extra terminal running to make signed commits using VS Code.