enable release-go plugin in stable-4.0 branch

[ScharfViktor]

I noticed that if I merge PR to stable-4.0 readyReleaseGo doesn't create Release PR because "when": was "main"

def readyReleaseGo():
    return [{
        "name": "ready-release-go",
        "steps": [
            {
                "name": "release-helper",
                "image": READY_RELEASE_GO,
                "settings": {
                    "git_email": "[email protected]",
                    "forge_type": "github",
                    "forge_token": {
                        "from_secret": "github_token",
                    },
                },
            },
        ],
        "when": [event["base"]],
    }]