name: Deploy
on:
  push:
    branches: [ main ]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Install Hugo
        run: sudo apt-get install hugo
      - name: Build
        run: hugo -d www/

name: Deploy
on:
  push:
    branches: [ main ]
jobs:
  build:
    runs-on: ubuntu-latest
    env: 
      HUGO_VERSION: "0.73.0"
    steps:
      - uses: actions/checkout@v2
      - name: Install Hugo
        run: curl -LO https://github.com/gohugoio/hugo/releases/download/v${HUGO_VERSION}/hugo_${HUGO_VERSION}_Linux-64bit.deb && sudo dpkg -i hugo_${HUGO_VERSION}_Linux-64bit.deb
      - name: Build
        run: hugo -d www/

Install more recent hugo version
Install more recent hugo version

apt's version is a bit old
