feat: add extra overload for concat for when it is not known statically whether inputs are eager or lazy #3337

	name: Random Versions

	on:
	pull_request:

	jobs:
	tox:
	strategy:
	matrix:
	python-version: ["3.9"]
	os: [ubuntu-latest]

	runs-on: ${{ matrix.os }}
	steps:
	- uses: actions/checkout@v4
	- uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install uv
	uses: astral-sh/setup-uv@v5
	with:
	enable-cache: "true"
	cache-suffix: ${{ matrix.python-version }}
	cache-dependency-glob: "pyproject.toml"
	- name: generate-random-versions
	run: python utils/generate_random_versions.py
	- name: install-random-verions
	run: uv pip install -r random-requirements.txt --system
	- name: install-narwhals
	run: uv pip install -e ".[dev]" --system
	- name: show versions
	run: uv pip freeze
	- name: Run pytest
	run: \|
	pytest tests --cov=narwhals --cov=tests --cov-fail-under=80 \
	--constructors=pandas,pyarrow,polars[eager],polars[lazy]

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