Emit error when trying to set negative number of empty bands in DFT #4965

	# This workflow is used to check backwards compatibility

	name: Backwards

	on:
	push:
	branches: [ main ]
	pull_request:

	jobs:
	build:

	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v4
	- name: Merge environments
	run: \|
	cp .ci_support/environment.yml environment.yml
	tail --lines=+4 .ci_support/environment-notebooks.yml >> environment.yml
	- name: Setup Mambaforge
	uses: conda-incubator/setup-miniconda@v2
	with:
	python-version: '3.10'
	miniforge-variant: Mambaforge
	channels: conda-forge
	channel-priority: strict
	activate-environment: my-env
	environment-file: environment.yml
	use-mamba: true
	- name: Test
	shell: bash -l {0}
	run: \|
	python .ci_support/pyironconfig.py
	./.ci_support/test_backwards.sh

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