feat(lib): propagate manim render exit code

[chrjabs]

Fixes Issue

Closes #544

Description

Propagate the exit code of manim render when invoking manim-slides render.

Check List

Check all the applicable boxes:

• I understand that my contributions needs to pass the checks;
• If I created new functions / methods, I documented them and add type hints;
• If I modified already existing code, I updated the documentation accordingly;
• The title of my pull request is a short description of the requested changes.

Screenshots

Note to reviewers

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.10%. Comparing base (0c6cd67) to head (4b53f21).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #545   +/-   ##
=======================================
  Coverage   80.09%   80.10%           
=======================================
  Files          23       23           
  Lines        2025     2026    +1     
=======================================
+ Hits         1622     1623    +1     
  Misses        403      403           

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[jeertmans]

Thanks for your contribution @chrjabs!

For this to be complete, could you:

• include a short explanation of your addition in the CHANGELOG, see other lines as examples:

  manim-slides/CHANGELOG.md

  Lines 10 to 20 in 0c6cd67

  	(unreleased)=
  	## [Unreleased](https://github.com/jeertmans/manim-slides/compare/v5.5.1...HEAD)
  	(unreleased-chore)=
  	### Chore
  	- Moved `docs` and `tests` extras, as well as `dev-dependencies`,
  	inside groups in `dependency-groups`. This could break existing code
  	when using one of those extras, but as they were not part of the public API,
  	we do not consider this to be a **breaking change**.
  	[#542](https://github.com/jeertmans/manim-slides/pull/542)

  
  You can add something like this:

  (unreleased-added)=
  ### Added
  
  - `manim-slides render` now exists with the same return code as the one returned by `manim render` or `manimgl`.
    [@chrjabs](https://github.com/chrjabs) [#545](https://github.com/jeertmans/manim-slides/pull/545)

• add a new test, e.g., you copy this tests

  manim-slides/tests/test_slide.py

  Lines 62 to 91 in 0c6cd67

  	@pytest.mark.parametrize(
  	"renderer",
  	[
  	"--CE",
  	pytest.param(
  	"--GL",
  	marks=pytest.mark.skipif(
  	sys.version_info < (3, 10),
  	reason="See https://github.com/3b1b/manim/issues/2263.",
  	),
  	),
  	"--CE --renderer=opengl",
  	],
  	ids=("CE", "GL", "CE(GL)"),
  	)
  	def test_render_basic_slide(
  	renderer: str,
  	slides_file: Path,
  	presentation_config: PresentationConfig,
  	manimgl_config: Path,
  	) -> None:
  	runner = CliRunner()
  	with runner.isolated_filesystem() as tmp_dir:
  	shutil.copy(manimgl_config, tmp_dir)
  	results = runner.invoke(
  	render, [*renderer.split(" "), str(slides_file), "BasicSlide", "-ql"]
  	)
  	assert results.exit_code == 0, results

  and make sure that a non-working Manim construct results in a non-zero error code (e.g., you can use self.play("this fail")).

Let me know if that is unclear :-)

[chrjabs]

Thanks for the pointers. Feel free to squash when merging, or let me know what else is missing.
The new tests pass locally.

Test output

manim-slides [ render-exit-code][🐍 v3.13.3]
❯ uv run pytest tests/test_slide.py::test_render_failing_slide
=============================================================================================== test session starts ================================================================================================
platform linux -- Python 3.11.12, pytest-8.3.4, pluggy-1.5.0
PySide6 6.8.1 -- Qt runtime 6.8.1 -- Qt compiled 6.8.1
rootdir: /home/christoph/Git/manim-slides
configfile: pyproject.toml
plugins: missing-modules-0.2.1, cov-6.0.0, env-1.1.5, qt-4.4.0
collected 3 items

tests/test_slide.py ...                                                                                                                                                                                      [100%]

---------- coverage: platform linux, python 3.11.12-final-0 ----------
Coverage XML written to file coverage.xml


================================================================================================ 3 passed in 19.90s ================================================================================================

[jeertmans]

Looks great, thanks for your contribution @chrjabs!