force new FFMPEG.jl version for tests

[ranocha]

This should fix our recent CI failures on Windows and macOS related to ancient versions of FFMPEG, e.g.,

• https://github.com/trixi-framework/Trixi.jl/actions/runs/8170243302/job/22336021936?pr=1857#step:7:45
• https://github.com/trixi-framework/Trixi.jl/actions/runs/8170243302/job/22336022461?pr=1857#step:7:45

It looks like the reason is that the package manager prefers a newer version of FFMPEG_jll that is not yet allowed by FFMPEG.jl (but there is the PR JuliaIO/FFMPEG.jl#59):
I was able to reproduce getting the old version as follows.

1. Remove Manifest.toml and use the current clone of Trixi.jl
2. julia +1.9 --project=.
3. (Trixi) pkg> build
4. julia> ENV["TRIXI_TEST"] = "none"
5. (Trixi) pkg> test Trixi

Then, I inspected the generated Manifest.toml:

(debug) pkg> status --manifest --outdated
Status `debug/Manifest.toml`
...
⌃ [c87230d0] FFMPEG v0.2.4 (<v0.4.1)

Updating yields

(debug) pkg> add FFMPEG@v0.4
   Resolving package versions...
    Updating `debug/Project.toml`
  [c87230d0] + FFMPEG v0.4.1
    Updating `debug/Manifest.toml`
  [b99e7846] - BinaryProvider v0.5.10
  [c87230d0] ↑ FFMPEG v0.2.4 ⇒ v0.4.1
⌅ [b22a6f82] ↓ FFMPEG_jll v6.1.1+0 ⇒ v4.4.4+1

Let's see whether it works.

Closes #1852

[github-actions]

Review checklist

This checklist is meant to assist creators of PRs (to let them know what reviewers will typically look for) and reviewers (to guide them in a structured review process). Items do not need to be checked explicitly for a PR to be eligible for merging.

Purpose and scope

• The PR has a single goal that is clear from the PR title and/or description.
• All code changes represent a single set of modifications that logically belong together.
• No more than 500 lines of code are changed or there is no obvious way to split the PR into multiple PRs.

Code quality

• The code can be understood easily.
• Newly introduced names for variables etc. are self-descriptive and consistent with existing naming conventions.
• There are no redundancies that can be removed by simple modularization/refactoring.
• There are no leftover debug statements or commented code sections.
• The code adheres to our conventions and style guide, and to the Julia guidelines.

Documentation

• New functions and types are documented with a docstring or top-level comment.
• Relevant publications are referenced in docstrings (see example for formatting).
• Inline comments are used to document longer or unusual code sections.
• Comments describe intent ("why?") and not just functionality ("what?").
• If the PR introduces a significant change or new feature, it is documented in NEWS.md.

Testing

• The PR passes all tests.
• New or modified lines of code are covered by tests.
• New or modified tests run in less then 10 seconds.

Performance

• There are no type instabilities or memory allocations in performance-critical parts.
• If the PR intent is to improve performance, before/after time measurements are posted in the PR.

Verification

• The correctness of the code was verified using appropriate tests.
• If new equations/methods are added, a convergence test has been run and the results
  are posted in the PR.

Created with ❤️ by the Trixi.jl community.

[ranocha]

CI is still running, so it looks like this hotfix works for now.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.28%. Comparing base (e205b06) to head (3364410).
Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1858   +/-   ##
=======================================
  Coverage   96.28%   96.28%           
=======================================
  Files         438      438           
  Lines       35386    35386           
=======================================
  Hits        34071    34071           
  Misses       1315     1315           

Flag	Coverage Δ
unittests	96.28% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[sloede]

Thanks!

[JoshuaLampert]

Thanks!