https://blog.saitho.me/manual-steps-in-automated-quality-pipeline

integrationtest-by-approval.yml

name: Triggered by PR approval
on:
  pull_request_review:
    types: [submitted]
  # execute integration test when maintainer approves pull request ("success" signal of manual workflow)
  integrationtest:
    name: Run integration test
    runs-on: ubuntu-latest
    if: github.event.pull_request.draft == false
    steps:
      - run: if [ ${{ github.event.review.state }} != 'approved' ]; then exit 1; else exit 0; fi
      - run: echo "Run Integration tests here..." 

integrationtest-by-label.yml

name: Triggered by label

on:
  pull_request:
    types: [labeled, synchronize]

jobs:
  # execute integration test when maintainer sets label "action/integration-test" as "success" signal of manual workflow
  integrationtest:
    name: Integration Test
    runs-on: ubuntu-latest
    if: github.event.pull_request.draft == false
    steps:
      - run: if [ ${{ contains( github.event.pull_request.labels.*.name, 'action/integration-test') }} == false ]; then exit 1; else exit 0; fi
      - run: echo "Run Integration tests here..." 

tests.yml

name: Test
on:
  pull_request:
    types: [opened, synchronize, reopened]
jobs:
  build:
    name: Lint Code Base
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Code
        uses: actions/checkout@v2
        with:
          fetch-depth: 0
      - name: Lint Code Base
        uses: docker://github/super-linter:v3
        env:
          VALIDATE_ALL_CODEBASE: false
          DEFAULT_BRANCH: main
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
  sonarcloud:
    name: SonarCloud
    runs-on: ubuntu-latest
    needs: build
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
      - name: SonarCloud Scan
        uses: SonarSource/sonarcloud-github-action@master
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}  # Needed to get PR information, if any
          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
  unittest:
    name: Run unit tests
    runs-on: ubuntu-latest
    steps:
      - run: echo "Run Unit tests here..."
  # notify maintainer that that they need to do a code review ("trigger" manual workflow)
  assignreviewer:
    name: Assign Reviewer
    runs-on: ubuntu-latest
    needs: sonarcloud
    steps:
      - uses: AveryCameronUofR/add-reviewer-gh-action@1.0.3
        with: 
          reviewers: "YOUR-USERNAME"
          token: ${{ secrets.GITHUB_TOKEN }}