setup-forgejo/renovate.json

{
    "$schema": "https://docs.renovatebot.com/renovate-schema.json",
    "extends": ["local>actions/renovate-config"],
    "customManagers": [
        {
            "description": "update runner in RUNNER_VERSION",
            "fileMatch": ["RUNNER_VERSION"],
            "matchStrings": ["^(?<currentValue>v\\d+\\.\\d+\\.\\d+)$"],
            "datasourceTemplate": "docker",
            "depNameTemplate": "data.forgejo.org/forgejo/runner"
        },
        {
            "description": "update runner in README.md",
            "fileMatch": ["README.md"],
            "matchStrings": [
                "| runner-version | .+? | (?<currentValue>v\\d+\\.\\d+\\.\\d+) |"
            ],
            "datasourceTemplate": "docker",
            "depNameTemplate": "data.forgejo.org/forgejo/runner"
        },
        {
            "description": "update runner in action.yml",
            "fileMatch": ["action.yml"],
            "matchStrings": [
                "\\s+runner-version:\\s+description: .+?\\s+default: (?<currentValue>v\\d+\\.\\d+\\.\\d+)\\s"
            ],
            "datasourceTemplate": "docker",
            "depNameTemplate": "data.forgejo.org/forgejo/runner"
        }
    ]
}