Can't unmute audio in video embeds

[Daniel-Aaron-Bloom]

• Extension version: 0.128.0
• VSCode Version: 1.109.5 (Universal)
• OS: Darwin arm64 25.3.0
• Repository Clone Configuration (single repository/fork of an upstream repository): single repository
• GitHub Product (GitHub.com/GitHub Enterprise version x.x.x): GitHub.com/

Steps to Reproduce:

1. Create a PR
2. Embed a video with audio in a comment or PR description (e.g. https://github.com/user-attachments/assets/8413e640-59e9-490e-861d-49187e967526)
3. Open the PR and see the embed
4. Note that the audio button is greyed out
5. Be sad

Perhaps relatedly, on every browser I've tried, having a webm with only an audio stream generally works (albeit in an ugly way), but in the extension the entire embed is greyed out.