Add platform info utilities to @actions/core

[nikolai-laevskii]

Adds shorthands for getting information about platform action is running on:

import { platform } from '@actions/core'

/* same as os.platform() */
platform.platform // 'win32' | 'darwin' | 'linux' | 'freebsd' | 'openbsd' | 'android' | 'cygwin' | 'sunos'

/* same as os.arch() */
platform.arch // 'x64' | 'arm' | 'arm64' | 'ia32' | 'mips' | 'mipsel' | 'ppc' | 'ppc64' | 'riscv64' | 's390' | 's390x'

/* common shorthands for platform-specific logic */
platform.isWindows // true
platform.isMacOS // false
platform.isLinux // false

/* run platform-specific script to get more details about the exact platform, works on Windows, MacOS and Linux */
const {
  name, // Microsoft Windows 11 Enterprise
  version, // 10.0.22621
} = await platform.getDetails()

[dhensby]

I just want to say that I really appreciate this bit of functionality - thanks @nikolai-laevskii - it's allowed me to remove some custom code from my own action 🎉