WIP update actions

.github/workflows/pdf.yml

@@ -1,39 +1,17 @@
-# While this action's image (https://github.com/xu-cheng/texlive-action,
-# ghcr.io/xu-cheng/texlive-full:latest) is "only" 2 GiB, as opposed to
-# texlive/texlive with a whopping 4 GiB (!!), it already fails when "apk add
-# make". Also using the image as is instead of the "action" (which just
-# shell-execs the string below "run" :)) fails when pulling it from ghcr.io. So
-# 4 GiB it is, then.
-
-##jobs:
-## pdf:
-## runs-on: ubuntu-latest
-##
-## steps:
-## - name: checkout
-## uses: actions/checkout@v2
-##
-## - name: build
-## uses: xu-cheng/texlive-action/full@master
-## with:
-## run: |
-## apk update && apk add make && sh .github/scripts/build_pdf.sh built_pdfs
-
-
 name: Build and release PDF
 
 on: push
 
 jobs:
  pdf:
- runs-on: ubuntu-latest
+ runs-on: ubuntu-22.04
 
  container:
- image: texlive/texlive
+ image: texlive/texlive:latest-medium
 
  steps:
  - name: checkout
- uses: actions/checkout@v2
+ uses: actions/checkout@v4
 
  - name: build
  run: |