Allow mzz.combine where selector is not a string #621

	name: "Pull Request Docs Check"
	on:
	- pull_request

	jobs:
	docs:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- uses: mamba-org/setup-micromamba@v1
	with:
	environment-file: ci/environment-docs.yml
	- name: make docs
	shell: bash -l {0}
	run: \|
	cd docs
	make html

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