Stabilize video-feature CI install step on ubuntu-latest

[Copilot]

The scheduled workflow job Build and test --features video: ubuntu-latest, stable was failing before build/test due to intermittent apt package resolution (404 during FFmpeg dependency install). This change hardens the dependency install path so the job can reliably reach the Rust build stage.

• Root cause addressed

  • Refresh apt indexes before installing FFmpeg-related system packages in .github/workflows/check-compile.yaml.

• Workflow changes

  • Updated the install step to run apt-get update followed by apt-get install.
  • Removed a duplicate libavutil-dev entry from the package list.
  • Corrected step label typo (ffmepg → ffmpeg) for clarity.

- name: Install ffmpeg dependencies
  run: |
    sudo apt-get update
    sudo apt-get install -y clang libavcodec-dev libavformat-dev libavutil-dev pkg-config ffmpeg libavfilter-dev libavdevice-dev