🌟 [Major]: Introducing Install-PowerShell action

[MariusStorhaug]

Description

This pull request introduces the Install-PowerShell GitHub Action, simplifying installation of specific versions of PowerShell on GitHub runners.

Features:

• Cross‑platform installer – Runs on all GitHub‑hosted runners (Ubuntu, macOS, Windows). Detects the OS at runtime and executes the appropriate installation routine.
• Version selector – Installs either a specific PowerShell Core version (e.g. 7.4.1) or the latest stable release when Version: latest is supplied (default).
• Smart skip logic – Checks the currently installed PowerShell version and skips installation when the requested version is already present, saving time and CI minutes.
• Native package managers first
  • Linux (Debian/Ubuntu): Uses APT, falling back to direct .deb download if the exact version isn’t in the repo.
  • macOS: Prefers Homebrew Cask; falls back to the official .pkg installer (ARM64/x64 aware).
  • Windows: Downloads the official MSI and installs silently with msiexec.

Metadata Updates:

• Action Metadata Update: Updated action.yml to reflect the new functionality, including a description, branding changes, and streamlined inputs. Removed unnecessary inputs like Debug and Verbose. action.yml

Type of change

• 📖 [Docs]
• 🪲 [Fix]
• 🩹 [Patch]
• ⚠️ [Security fix]
• 🚀 [Feature]
• 🌟 [Breaking change]

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas

[Copilot]

Pull Request Overview

This pull request introduces the Install-PowerShell action with support for installing PowerShell on Windows, Ubuntu, and macOS, and updates the test workflow to run on multiple operating systems with specified versions.

• Renames and describes the action to clearly indicate its purpose.
• Replaces the placeholder test file and updates the composite action steps across different operating systems.
• Adds a matrix strategy in the workflow to test multiple OS and PowerShell versions.

Reviewed Changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

File	Description
tests/README.md	Removed the placeholder file for tests
action.yml	Updated action metadata and composite run steps across platforms
.github/workflows/Action-Test.yml	Updated test workflow with a matrix strategy for OS/version testing

Files not reviewed (1)

• scripts/main.ps1: Language not supported

Comments suppressed due to low confidence (1)

action.yml:21

• The input key is defined as 'Version' in the inputs block but is referenced as 'inputs.version'; ensure consistent casing to avoid potential issues.

$version = '${{ inputs.version }}'