Update fr web translation for 3.12.0

[ann0see]

Hi @jujudusud, @trebmuh,

We are getting ready for the 3.12.0 release and have created the next-release branch (full diff).

We would be happy if you updated the translations for fr by 2025-10-21.

Please either update the translations on Hosted Weblate, or use Git:

• Start your work in your fork on a branch based on jamuluswebsite's next-release branch.
• Update the language-specific files using your favourite editor (or directly on GitHub),
• New/changed images are listed at the end of this issue. Generate new URLs for your image .inc files.
• Commit and push your changes to your fork,
• Open a Pull Request with your translations to the next-release branch with the subject Update fr web translation for 3.12.0,
• Link your PR(s) to this issue by including Fixes #1101 in the PR content.

This Issue is assigned to multiple people. Please coordinate who will translate what part.

Suggested commit and PR message:

Update fr web translation for 3.12.0

Fixes #1101

Feel free to use this Issue to discuss anything you need prior to making any PR (and in your native language if needed).

Further documentation can be found in TRANSLATING.md.

Thanks for contributing to Jamulus!

---

New/Changed screenshots:

Please replace with new URLs for your screenshots here, and use those URLs in your .inc files.

Connection dialog: