Update actions/checkout action to v4 #30

	name: CI

	on:
	push:
	branches: [ main ]
	pull_request:
	branches: [ main ]

	env:
	REGISTRY: ghcr.io
	IMAGE_NAME: ${{ github.repository }}

	jobs:
	build:
	name: Build Docker image
	runs-on: ubuntu-latest
	steps:
	- name: Checkout repository
	uses: actions/checkout@v4
	- name: Process metadata (tags, labels)
	id: meta
	uses: docker/metadata-action@v4
	with:
	images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
	- name: Build and push Docker image
	uses: docker/build-push-action@v5
	with:
	context: .
	push: false
	tags: ${{ steps.meta.outputs.tags }}
	labels: ${{ steps.meta.outputs.labels }}

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