Update docker/build-push-action action to v6 #273

	# This is a basic workflow to help you get started with Actions

	name: Build

	# Controls when the workflow will run
	on:
	# Triggers the workflow on push events for all branches
	push:
	pull_request:
	branches:
	- main
	- master

	# Allows you to run this workflow manually from the Actions tab
	workflow_dispatch:

	# A workflow run is made up of one or more jobs that can run sequentially or in parallel
	jobs:
	# This workflow contains a single job called "build_latex"
	build:
	# The type of runner that the job will run on
	runs-on: ubuntu-latest
	container:
	image: ghcr.io/tudalgo/algotex:latest

	# Steps represent a sequence of tasks that will be executed as part of the job
	steps:
	# 1. Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
	- name: Set up Git repository
	uses: actions/checkout@v3

	# 5. Run l3build
	- name: Run l3build
	run: l3build ctan -H

	# 6. Upload artifacts to GitHub
	- name: Upload artifacts to GitHub
	uses: actions/upload-artifact@v3
	with:
	name: CTAN Archives
	path: "*.zip"
	if-no-files-found: error

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