Detect CI Environment

The `is-ci` package provides a minimalist, direct method for determining whether the current process is executing within a Continuous Integration (CI) environment. It exposes a simple boolean value (`true` if running in CI, `false` otherwise), abstracting away the complexities of checking various environment variables across different CI providers. The current stable version is `4.1.0`. The library typically sees updates in conjunction with its underlying dependency, `ci-info`, which is responsible for the core detection logic, leading to an irregular but feature-driven release cadence. Its primary differentiator is its singular focus on providing a simple boolean answer, making it ideal for conditional logic in build scripts, test runners, or deployment pipelines where CI context is crucial. It supports a wide array of CI services by leveraging `ci-info`'s comprehensive detection capabilities.