feat: Add code completion and annotator support for steps.*.{conclusion,outcome}

[YunaBraska]

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Motivation

Why is this change required? What problem does it solve?

Code completion and annotation is incomplete for items under steps.* other than outputs.

Changes

Behaviour, Functionality, Screenshots, etc.

This pull request adds code completion and annotator support for steps.*.conclusion and steps.*.outcome. These properties are documented at https://docs.github.com/en/actions/learn-github-actions/contexts#steps-context.

Success Check

How can we see or measure the change?

Try opening this simple workflow:

name: checks

on:
  pull_request: ~

jobs:
  checks:
    runs-on: ubuntu-22.04
    steps:
      - uses: actions/checkout@v4
        id: checkout

      - run: echo "${{ steps.checkout.outcome }}"